CancerXpress

CancerXpress is a pan-cancer transcriptomic representation learning framework for bulk RNA-seq data. It learns de-batched expression profiles and transferable biological representations that can be used for downstream prediction, functional state analysis, and interpretable single-sample characterization.

It is designed for use cases where transcriptomic models need to generalize across cohorts, sequencing workflows, and cancer types rather than only perform well within a single dataset.

Key Features

• batch effect correction and corrected expression reconstruction
• latent embedding extraction for downstream analysis
• pan-cancer representation learning across cohorts and cancer types
• functional-axis prediction
• survival risk prediction with external cohort evaluation
• functional state characterization through low-dimensional transcriptomic axes
• sample-level attribution through integrated gradients
• hierarchical gene-to-axis-to-risk attribution with exact functional-axis Shapley, matched baselines, and completeness diagnostics
• automatic gene ID conversion between Ensembl IDs and HGNC symbols
• legacy research training scripts under training/ (outside the package runtime compatibility matrix)

This release provides representation/batch correction, functional-axis and risk prediction, attribution, reference search and target-cohort adaptation. It does not provide cancer-type or primary-site prediction, plotting functions, or automatic reference-data installation. Cancer type remains a user-supplied clinical/biological label. Outputs are for research, not clinical diagnosis.

Quick Start

CancerXpress 1.2.0 introduces biological functional-axis names and automatic input validation. When upgrading from 1.1, update the old method and axis names as described in the migration guide.

Choose one of the two installation methods:

Method	Current version	Python
Download the GitHub project and install locally	1.2.0	3.8-3.13; 3.11 or 3.12 recommended
Install from PyPI	1.2.0	3.8-3.13; 3.11 or 3.12 recommended

Prepare the separate model bundle before inference. Follow the step-by-step tutorial for TPM inputs, prediction, attribution, local reference queries and optional cohort adaptation. The tutorial includes a reproducible synthetic-data walkthrough and explains how to substitute real data; synthetic results are not biological validation.

The older PyPI 1.0.0 release supports Python 3.8 only. Do not apply its historical requirements-release-lock.txt constraints to versions 1.1 or later.

The examples below use files from the GitHub project. A PyPI installation does not include those example files; download the project or use your own TPM and clinical files.

Run the full inference pipeline on the example data:

cancerxpress \
  --input examples/scanb_demo_3samples.tsv \
  --clinical-file examples/scanb_demo_3samples_label.tsv \
  --outdir output/demo \
  --task all \
  --gene-id-type ensembl

Run survival risk prediction only:

cancerxpress \
  --input examples/scanb_demo_3samples.tsv \
  --clinical-file examples/scanb_demo_3samples_label.tsv \
  --outdir output/risk_demo \
  --task risk \
  --gene-id-type ensembl

Use the Python API:

import pandas as pd
import cancerxpress as cx

expr = pd.read_csv('examples/scanb_demo_3samples.tsv', sep='\t', index_col=0)
clinical = pd.read_csv('examples/scanb_demo_3samples_label.tsv', sep='\t', index_col=0)

model = cx.CancerXpress()
latent, corrected = model.batch_correct(expr, gene_id_type='ensembl')
functional_axis_predictions = model.predict_functional_axes(expr, gene_id_type='ensembl')
risk_scores = model.predict_survival_risk(expr, clinical=clinical, gene_id_type='ensembl')

Run the standalone survival risk example:

python examples/risk_prediction_demo.py

Run the standalone survival risk attribution example:

python examples/risk_attribution_demo.py

Project Layout

• cancerxpress/: installable Python package
• resources/: required assets, encoders, mappings, and model manifests/checkpoints
• training/: key training and fine-tuning scripts
• examples/: small example input files
• tutorials/: step-by-step workflows and interpretation notes

Packaged Models

• resources/models/pretrained/batch_correction/ Model parameters for batch correction, latent embedding extraction, and corrected expression reconstruction.
• resources/models/finetuned/functional_axes/ Model parameters for functional-axis prediction.
• resources/models/finetuned/survival_risk/ Model parameters for survival risk prediction.

Model parameters and reference data are installed manually and are not included in this package. Keep the supplied bundle layout unchanged; older bundles may contain unused classification checkpoints, which this API does not load.

Installation

The current runtime supports Python 3.8-3.13, with TensorFlow 2.13.x on Python 3.8 and TensorFlow / tf-keras 2.20.x on Python 3.9-3.13. TensorFlow Addons is no longer required. Keras 2 checkpoint compatibility is handled internally without changing the process-wide Keras selection.

Python 3.14 and later are not yet advertised as supported. See Installation and Compatibility for runtime requirements and the model-regression test procedure.

Option 1: Download the GitHub Project and Install Locally

Use a dedicated Python 3.8-3.13 environment. This option includes the source, tutorials, and example files. Download the project using Git:

git clone https://github.com/Qiankun-1024/CancerXpress.git
cd CancerXpress
python -m pip install --upgrade pip
python -m pip install .

Alternatively, select Code > Download ZIP on the GitHub repository, extract it, and run python -m pip install . inside the extracted CancerXpress-main directory. Git is not needed for the ZIP method.

If you plan to edit the source, use python -m pip install -e . instead. For reproducibility, use a specific Git commit or release tag rather than a moving branch.

Option 2: Install from PyPI

Install CancerXpress 1.2.0 from PyPI in a dedicated Python 3.8-3.13 environment:

python -m pip install --upgrade pip
python -m pip install "cancerxpress==1.2.0"
python -m pip check

Both installation methods provide the functional-axis interfaces shown below.

To upgrade an existing installation, use python -m pip install --upgrade cancerxpress. Use a fresh environment when migrating from 1.0.0 to avoid retaining obsolete TensorFlow GPU / Addons dependencies. The historical requirements-release-lock.txt can be used as pip constraints to reproduce the tested 1.0.0 dependency versions; do not apply that file to versions 1.1 or later.

Both methods install code and dependencies only. Model parameters and reference data remain separate and must be installed manually. Prepare the local model files as described in Model Resources and Paths before running predictions.

Read the Docs

The repository includes mkdocs.yml and .readthedocs.yaml. The documentation build installs only docs/requirements.txt, not TensorFlow or model resources. See Documentation Deployment for local preview and the required account-level GitHub connection. The configuration alone does not create a hosted Read the Docs project.

Model Resources and Paths

The wheel and source distribution contain code only, not model weights or patient data. The resource bundle includes inference checkpoints, gene mapping, normalization assets, label encoders and clinical preprocessing metadata.

Keep existing bundles unchanged. Legacy checkpoint directories, axis labels, and reference-database fields are translated internally when read. New API outputs use functional-axis terminology; no model retraining is involved.

import cancerxpress as cx

# Manually extract the model bundle to ~/.cache/cancerxpress/resources first.
# Construction and prediction never download missing files automatically.
model = cx.CancerXpress()

# Alternatively, use your own extracted bundle:
model = cx.CancerXpress(resource_dir="/path/to/resources")
# Override only weights if needed (assets still come from resource_dir):
model = cx.CancerXpress(
    resource_dir="/path/to/resources", model_dir="/path/to/other/models"
)
cx.verify_resources("/path/to/resources")

Set CANCERXPRESS_HOME to change the default resource root. Paths do not depend on the working directory. CLI equivalents are --resource-dir and --model-dir. For a local checkout using its existing resources, pass resource_dir="resources" explicitly. Do not mix weights and preprocessing assets from different releases.

The downloader requires HTTPS and the expected SHA-256, verifies every file, rejects unsafe archive paths, and never overwrites an existing destination. Only install bundles from a trusted publisher: label encoders use Python pickle. See Manually Install Reference Data for the resource and reference-directory layout. No published download URL is assumed.

Python API

Functional axes use biological names rather than color IDs. API arguments and output columns use the identifiers below, in the frozen model's output order:

API identifier	English label	中文名称
repair_proteostasis	Repair–proteostasis	修复–蛋白稳态
immune_inflammation	Immune inflammation	免疫炎症
hypoxia_myogenesis	Hypoxia–myogenesis	缺氧–肌样
inflammatory_stress	Inflammatory stress	炎症应激
stromal_remodeling	Stromal remodeling	基质重塑
developmental_regulation	Developmental regulation	发育调控
proliferation	Proliferation	细胞增殖
metabolism_detoxification	Metabolism–detoxification	代谢解毒

cancerxpress.FUNCTIONAL_AXIS_NAMES provides the identifiers and cancerxpress.FUNCTIONAL_AXIS_LABELS provides the en and zh display labels. This renames existing outputs without retraining the model or changing their order, numerical values, or risk-contribution directions.

The package checks expression values and identifiers internally. Clinical rows are aligned to expression sample IDs automatically. Duplicate/missing IDs, nonnumeric/nonfinite/negative TPM, and missing clinical samples raise descriptive errors; users do not need to write validation assertions before every call.

CancerXpress provides a single high-level entry point for preprocessing, prediction, and attribution:

import pandas as pd
import cancerxpress as cx

expr = pd.read_csv('examples/scanb_demo_3samples.tsv', sep='\t', index_col=0)
clinical = pd.read_csv('examples/scanb_demo_3samples_label.tsv', sep='\t', index_col=0)

model = cx.CancerXpress()
latent, corrected = model.batch_correct(expr, gene_id_type='ensembl')
functional_axis_predictions = model.predict_functional_axes(expr, gene_id_type='ensembl')
risk_scores = model.predict_survival_risk(
    expr,
    clinical=clinical,
    gene_id_type='ensembl',
)

functional_axis_attribution = model.attribute_functional_axis(expr.iloc[[0]], axis_name='immune_inflammation', gene_id_type='ensembl')
survival_risk_attribution = model.attribute_survival_risk(
    expr.iloc[[0]],
    clinical=clinical.iloc[[0]],
    gene_id_type='ensembl',
)

Main API methods:

• batch_correct(...)
• predict_functional_axes(...)
• predict_survival_risk(...)
• attribute_functional_axis(...)
• attribute_survival_risk(...)
• attribute_axis_risk(...)

Attribution covers functional axes and survival risk, not classification.

Survival Risk Prediction

The packaged survival risk model is the run1 functional-axis-and-clinical Cox model. CancerXpress first predicts the eight functional-axis scores from expression and then combines them with the clinical covariates. It requires:

• an expression matrix
• a clinical table containing age, sex, race, tumor_stage, and cancer_type

Required Input Format

Expression matrix:

• rows: samples
• columns: genes
• values: TPM-like expression matrix accepted by CancerXpress

Clinical file:

• same sample order as the expression matrix, or matching sample IDs in the first column
• must contain age, sex, race, tumor_stage, and cancer_type

Example clinical file:

sample_id	age	sex	race	tumor_stage	cancer_type
sample_1	62	female	white	Stage II	BRCA
sample_2	55	male	asian	Stage III	LUAD

Python Example

import pandas as pd
import cancerxpress as cx

expr = pd.read_csv('examples/scanb_demo_3samples.tsv', sep='\t', index_col=0)
clinical = pd.read_csv('examples/scanb_demo_3samples_label.tsv', sep='\t', index_col=0)

model = cx.CancerXpress()
risk_scores = model.predict_survival_risk(
    expr_tpm=expr,
    clinical=clinical,
    gene_id_type='ensembl',
)
print(risk_scores)

Survival Risk Attribution Example

import pandas as pd
import cancerxpress as cx

expr = pd.read_csv('examples/scanb_demo_3samples.tsv', sep='\t', index_col=0)
clinical = pd.read_csv('examples/scanb_demo_3samples_label.tsv', sep='\t', index_col=0)

sample_id = expr.index[0]

model = cx.CancerXpress()
attribution = model.attribute_survival_risk(
    expr_tpm=expr.loc[[sample_id]],
    clinical=clinical.loc[[sample_id]],
    gene_id_type='ensembl',
)

Reference Queries and Target-Cohort Adaptation

Manually Install Reference Data

The supported setup is currently local files supplied separately. No data hosting service, DOI, account or automatic download is required. Installing the Python package does not install model parameters or the reference database. Missing files produce an error rather than trigger a download.

Place the files in this layout (or choose any absolute directory):

~/.cache/cancerxpress/
  resources/                     # Model bundle, required for inference
    assets/                      # Keep the supplied bundle layout unchanged
    models/
    encoders/
    gene_annotation/
    mappings/
    resource_manifest.json
  reference/                     # Indexed data release, for sample retrieval
    reference_index.json.gz
    expression_samples_001.zip
    expression_samples_002.zip
    ...                          # Every ZIP named in reference_index.json.gz
    reference_atlas/              # Optional fast-loading query/adaptation atlas
      atlas.json
      samples.tsv
      features.npz

Do not unzip or rename the indexed ZIP files. They contain raw TPM, corrected expression, latent, functional-axis and sample metadata; these five components need not be copied again as separate tables. ZIP counts are defined by the release index, not hard-coded in the package.

Use case	Required reference files
Predict or attribute your own TPM	None; only the matching model/resource bundle
Query or adapt against a supplied atlas	atlas.json, samples.tsv, features.npz
Retrieve stored sample expression/features	reference_index.json.gz and all indexed ZIP shards

atlas.json records the format, feature column names and model/preprocessing signature. features.npz contains numeric latent and functional_axes arrays in exactly the row order of samples.tsv. The latter is a sample-indexed TSV with sample_id and cancer_type; additional biological labels are optional. Preserve missing reference labels. Do not combine feature files and models from different releases.

Read Specific Reference Samples

The indexed reference release uses uniform sample shards, not cancer-specific archives. Each sample's TPM, corrected expression and features are independently compressed inside an uncompressed ZIP container. A small index maps sample IDs to exact byte ranges and SHA-256 checksums. This is different from the historical whole-file .tar.gz release; those files cannot use this interface.

from cancerxpress import SampleDatabase

# Default: ~/.cache/cancerxpress/reference, or CANCERXPRESS_REFERENCE_DIR.
db = SampleDatabase.from_directory()
# Alternatively: db = SampleDatabase.from_directory("/data/cancerxpress/reference")
ids = db.sample_ids[:2]  # Replace with the desired IDs from this release.
data = db.fetch(ids, components=["raw_tpm", "functional_axes", "metadata"])
# data["raw_tpm"]: samples x genes; data["functional_axes"]: samples x functional axes.

Supported components: raw_tpm, corrected_expression, latent, functional_axes, metadata. Raw TPM and corrected expression preserve their original, potentially different gene columns. Missing metadata labels are not inferred. Latent/functional-axis use the frozen release model recorded in the index. Opening the directory checks shard presence and sizes; reading a component verifies its SHA-256. Local reads do not use the network or create duplicate component caches. Only requested components are read. CANCERXPRESS_REFERENCE_DIR controls reference data only; CANCERXPRESS_HOME controls model resources. Neither default depends on the working directory. Automatic data download can be added later without changing the local format. The existing explicit-URL transport is optional and is not needed for this workflow.

A reference atlas stores sample-indexed latent means, eight functional-axis values and biological labels generated with one frozen model. It does not ship inside the Python wheel. Use a supplied TCGA atlas or build one from reference TPM:

atlas = cx.ReferenceAtlas.load("/data/cancerxpress/reference/reference_atlas")
# If only the indexed release is available, read its features (not expression):
# atlas = db.to_atlas()  # All samples; can take time on a large reference.
# atlas.save("/data/cancerxpress/reference/reference_atlas")  # New directory only.
# Or build your own atlas from reference TPM with model.build_reference(...).

hits = model.query(
    new_tpm, atlas, metadata=new_metadata,
    space="latent", k=10, metric="cosine", same_cancer=True,
    gene_id_type="ensembl",
)
# Use space="functional_axes" for functional-axis similarity; same_cancer=False for cross-cancer search.

Expression tables are samples x genes in TPM; metadata is indexed by the same sample IDs and contains cancer_type. Missing reference cancer labels remain missing (never inferred or imputed) and are allowed in unrestricted queries. same_cancer=True requires a nonmissing query label; unlabelled reference rows are excluded. Nonmissing query cancer labels must occur in the atlas. Extra labels such as subtype or grade are optional. Feature spaces and checkpoint/preprocessing hashes must match. Query distances default to reference-only z-scored features; cosine similarity is 1-distance. Euclidean mode reports distance (similarity is NaN). These are not confidence scores or prognostic predictions. Self-exclusion uses exact sample ID.

Fit a shared target-only residual adapter while keeping the encoder/functional-axis head frozen:

fit = model.adapt(
    new_tpm, new_metadata, atlas,
    biological_labels=["subtype"],  # Omit for cancer-only alignment, including a single cancer.
    epochs=200, patience=25, gene_id_type="ensembl",
)
fit.save("cohort_adapter")
print(fit.metrics)  # Before/after held-out MMD and displacement, not clinical validation.

adapter = cx.LatentAdapter.load_adapter("cohort_adapter")
latent, functional_axes = model.encode_features(
    new_tpm, adapter=adapter, metadata=new_metadata, gene_id_type="ensembl"
)
hits = model.query(
    new_tpm, atlas, metadata=new_metadata, adapter=adapter,
    space="functional_axes", same_cancer=True, gene_id_type="ensembl"
)

Cancer type is ALWAYS part of the alignment strata. Additional labels must exist in both cohorts; unseen strata are rejected. No survival or NMF program labels are used automatically. Use genuine biology labels, not outcome-derived groups. Reference rows missing any requested biological label are excluded from fitting; target rows missing these labels are rejected rather than silently reassigned. Each stratum needs at least five independent patients in each cohort to create 60/20/20-style training/validation/test splits; that minimum is a software check, not evidence that a tiny cohort is statistically adequate. Provide patient_id to keep repeated assays in one partition. Otherwise IDs are assumed to identify independent patients.

The objective is equal-weight per-stratum RBF MMD + 0.05 latent displacement

• 0.02 pairwise-distance distortion. Only reference TRAINING samples determine normalization. Validation-only early stopping selects weights. Validation/test MMD uses at most the first 256 samples per stratum, deterministically; metrics record evaluated counts. Inspect saved split tables and biological preservation; smaller MMD is not proof of biological recovery. Adapter use is explicit and does not change the reference atlas or ordinary prediction/attribution calls. Current adapter support covers encode_features and query; risk/IG APIs do not automatically apply it. Do not mix adapted functional-axis with old gene attribution. Training/validation patients are not untouched external validation.

Historical TCGA OOF attribution tables and fixed-release-model query features are distinct outputs. Use the companion TCGA handoff README for definitions, QC, patient/gene ordering and the historical baseline differences.

CLI Example

cancerxpress \
  --input examples/scanb_demo_3samples.tsv \
  --clinical-file examples/scanb_demo_3samples_label.tsv \
  --outdir output/risk_demo \
  --task risk \
  --gene-id-type ensembl

Output

The risk prediction output is a table with one row per sample and one column:

• risk_score: relative Cox-model risk score

Interpretation:

• a higher risk_score means a higher predicted relative risk
• the score is mainly useful for ranking samples within a cohort or cancer setting
• it is not a direct survival probability

For attribution output:

• survival_risk_prediction.tsv: predicted risk score for the input sample
• survival_risk_attribution.tsv: gene-level integrated gradients attribution for survival risk

Axis-Specific Risk Attribution

Pass the patient's TPM, clinical information, and reference TPM samples. The package handles internal image conversion and computes exact functional-axis Shapley, gene-to-axis IG, and the selected axis's gene-level risk allocation.

import pandas as pd
import cancerxpress as cx

expr = pd.read_csv('patient_tpm.tsv', sep='\t', index_col=0)
clinical = pd.read_csv('clinical.tsv', sep='\t', index_col=0)
reference = pd.read_csv('training_reference_tpm.tsv', sep='\t', index_col=0)

result = cx.CancerXpress().attribute_axis_risk(
    expr.iloc[[0]], clinical.loc[expr.index[:1]],
    axis_name='developmental_regulation', reference_tpm=reference, gene_id_type='ensembl',
)
result.axis_shapley.to_csv('axis_shapley.tsv', sep='\t')
result.gene_risk_contribution.to_csv('gene_axis_risk.tsv', sep='\t')
print(result.diagnostics)

• Both TPM matrices have samples as rows and genes as columns. Use a fixed training reference from the corresponding cancer/model/fold, not the test patient itself or an external cohort recentered separately. Reference patients do not need clinical information; the target patient's clinical inputs stay fixed.
• Internally, reference samples are individually preprocessed and their model-input images averaged. The model prediction of this average supplies the functional-axis baseline. No image or functional-axis-reference file is required from the user. This baseline is NOT the mean of individual functional-axis predictions and may differ from earlier research results using an optimized training-mean-functional-axis baseline.
• Outputs: axis_shapley (eight axes), gene_to_axis_ig, gene_risk_contribution, and diagnostics (completeness errors and validity). Allocation is axis_shapley * gene_IG / sum(gene_IG), over all mapped genes. Values are signed log-risk allocations, not percentages or causal effects. Invalid allocations become NaN.
• This differs from direct gene-to-risk IG (attribute_survival_risk). Advanced primitives remain available: exact_axis_shapley, gene_axis_integrated_gradients, allocate_axis_risk, and optimize_axis_baseline.

CLI

Run the Full Inference Pipeline

cancerxpress \
  --input examples/scanb_demo_3samples.tsv \
  --clinical-file examples/scanb_demo_3samples_label.tsv \
  --outdir output/demo \
  --task all \
  --gene-id-type ensembl

Expected outputs:

• latent.tsv
• corrected_expression.tsv
• functional_axis_predictions.tsv
• survival_risk.tsv

Run Attribution from CLI

cancerxpress \
  --input examples/scanb_demo_3samples.tsv \
  --outdir output/attr_demo \
  --task attribution \
  --attribution-task functional_axis \
  --target-name immune_inflammation \
  --sample-id TCGA-A2-A0T2-01A \
  --gene-id-type ensembl

Expected outputs:

• attribution.tsv
• attribution_prediction.tsv

Input Expression with HGNC Symbols

If the input matrix uses gene symbols instead of Ensembl IDs:

cancerxpress \
  --input your_symbol_expression.tsv \
  --clinical-file your_clinical_data.tsv \
  --outdir output/run_symbol \
  --task all \
  --gene-id-type symbol

Training and Fine-Tuning

The GitHub checkout contains research training scripts under training/. They are not installed by the wheel or source distribution and are not a unified, supported pretraining API. The supported package adaptation entry point is model.adapt(...), described above. Repository-only scripts include:

• training/ME_regression.py: regression training for eight functional-axis targets
• training/improved_risk_prediction.py: survival risk model training

Example: functional-axis Training

python training/ME_regression.py \
  --data /path/to/expression_matrix.tsv \
  --label /path/to/functional_axis_targets.tsv \
  --ckpt-dir training_checkpoints/functional_axis_regressor

Example: Survival Risk Training

python training/improved_risk_prediction.py \
  --data /path/to/expression_matrix.tsv \
  --label /path/to/survival_labels.tsv \
  --test-batches external_batch_1 external_batch_2 \
  --holdout-cancer-types optional_cancer_type

What Was Not Migrated

The following content was intentionally not copied into CancerXpress:

• most prediction outputs under output/
• historical training logs
• historical checkpoints
• very large internal training matrices
• attribution scripts and attribution intermediate results

This keeps the project much cleaner for packaging, publication, and long-term maintenance.

Notes

• The packaged run1 survival model requires expression plus age, sex, race, tumor_stage, and cancer_type for every sample.
• Training scripts do not automatically download datasets. You need to provide your own expression matrices and labels.