For the complete documentation index, see llms.txt. This page is also available as Markdown.

Analysis methods

A catalogue of the analyses K-Pro can run on your data, the statistical methods behind them, and which datasets support each modality.

K-Pro runs published, peer-reviewed statistical methods on patient-level data across seven modalities: bulk RNA sequencing, whole exome sequencing (WES), single-cell RNA sequencing, spatial transcriptomics, H&E histomics, clinical variables, and multimodal combinations of these.

This page catalogues what each analysis does and when to use it. For the plots these analyses produce — with parameters, screenshots, and example prompts — see Example: Visualisations by modalities.

Bulk RNA sequencing

Bulk RNA-seq measures average gene expression across all cells in a sample, giving a robust and cost-effective basis for transcriptomic profiling, biomarker discovery, and molecular subtyping.

Differential expression

  • Differential expression (DESeq2): identifies genes expressed differently between two clinical groups using the DESeq2 negative binomial model. Supports covariate adjustment for confounders such as age, gender, or tumour stage.

  • Differential expression (t-test): a modality-agnostic alternative using Welch's t-test, suitable for normalized expression data or when DESeq2 assumptions do not hold.

Survival and prognosis

  • Survival analysis (Cox): Cox proportional hazards modelling of the effect of gene expression on overall survival (OS) or progression-free survival (PFS). Supports univariate models, multivariate models combining genes with clinical covariates, and interaction analyses across expression-defined subgroups.

  • Kaplan-Meier analysis: survival curves stratified by expression level (for example high vs. low on a median cutoff) or another grouping variable.

  • Covariate-adjusted survival: Kaplan-Meier-style curves that control for clinical covariates, isolating the independent effect of expression on survival.

Pathways and signatures

  • ssGSEA enrichment: single-sample gene set enrichment, scoring each sample for pathway or signature activity so groups can be compared without a predefined contrast.

  • GSEA (preranked): gene set enrichment on a ranked gene list, such as the output of a differential expression analysis, returning a normalized enrichment score per pathway.

  • Gene signature scoring: custom signature scores across samples, for comparing biological programs such as immune signatures, metabolic pathways, or stemness scores.

Clustering and subtyping

  • Consensus agglomerative clustering: discovers patient subgroups from expression features, using bootstrap aggregation for robust subtype identification.

  • Feature extraction: identifies the minimal gene set that distinguishes subgroups or predicts an outcome, via Orthogonal Matching Pursuit or elastic-net stability selection. Reports per-gene selection frequency alongside ROC-AUC, accuracy, and F1.

  • Complex heatmap: clustered gene-panel heatmaps annotated with clinical variables, mutation status, or other categorical tracks.

Expression distributions

  • Single-gene, multi-gene, and signature expression: distributions across patient groups, for one gene, a panel, or a signature.

  • Expression variability: average variability of genes across groups, identifying those with high inter-patient heterogeneity.

  • Correlation analysis: pairwise Pearson or Spearman correlation between genes, proteins, or signatures, revealing co-expression and regulatory relationships.

  • Scatter/UMAP: sample embeddings via UMAP or PCA, coloured by metadata or continuous expression.

Example use cases
  • Volcano plot of genes differentially expressed between responders and non-responders

  • Tumour vs. adjacent normal tissue comparison with DESeq2

  • Differential expression between stages, adjusted for age and gender

  • CD8A expression by tumour stage (violin plot)

  • Clustered heatmap of immune checkpoint genes across patients

  • IFN-gamma signature scores in IO-treated vs. untreated patients

  • Kaplan-Meier curves for PD-L1 high vs. low expressors

  • Forest plot of a multivariate prognostic model combining signatures and clinical variables

  • Hallmark pathway activity across tumour subtypes with ssGSEA

  • Expression-based patient subtypes with consensus clustering

  • UMAP of patients coloured by histological subtype

Whole exome sequencing (WES)

WES captures protein-coding regions, enabling identification of somatic mutations and copy number variations (CNVs).

  • Mutation frequency analysis: per-position mutation frequency across a cohort, identifying hotspots within a gene. Supports variant allele frequency (VAF) display per patient, distinguishing clonal from subclonal mutations.

  • Oncoprint analysis: a genes × samples alteration matrix showing mutations and CNVs across a gene panel, characterising the mutational landscape and revealing co-occurrence and mutual exclusivity.

  • Alteration co-occurrence: co-occurrence of alterations (for example TP53 and ERBB2), stratified by clinical variables such as gender or stage.

  • Survival with genomic stratification: mutation status against OS or PFS via Cox models or Kaplan-Meier curves, with multivariate adjustment for clinical covariates.

  • Expression-alteration integration: expression heatmaps annotated by WES-derived CNV status, showing how genomic alterations track with transcriptional change.

Example use cases
  • Oncoprint of TP53, KRAS, and EGFR alterations across NSCLC patients

  • Lollipop plot of KRAS mutation hotspots (G12C, G12D)

  • Survival curves comparing TP53-mutant and wild-type patients

  • EGFR/TP53 co-occurrence by stage (stacked bars)

Single-cell RNA sequencing

Single-cell RNA-seq resolves cellular heterogeneity, revealing cell states, rare populations, and intercellular communication.

  • Sparse aggregation: percent-expressing cells and mean expression per group for a gene panel across cell types — the basis for single-cell dotplots.

  • Proportion analysis: cell-type composition per sample, showing how populations vary across patient groups or conditions.

  • Cell-cell communication: ligand-receptor signalling between cell types, inferred with LIANA and supporting CellChat, CellPhoneDB, and NATMI scoring.

  • Co-expression analysis: Jaccard-index overlap between two genes or signatures, quantifying the fraction of cells expressing only A, only B, or both.

  • Sparse correlation: pairwise Pearson or Spearman correlation between features, optionally stratified by cell type, to find co-regulated modules.

  • UMAP visualisation: single-cell embeddings coloured by metadata or continuous expression.

  • Pseudobulk differential expression: aggregates single-cell counts to patient-level profiles, then runs DESeq2 between clinical groups — across all cells or within one cell type.

  • InferCNV: infers copy-number variation from single-cell expression, clustering CNV profiles into clones via Leiden clustering.

  • Single-cell enrichment (ssGSEA): pathway and signature activity scored per cell or per pseudobulk sample.

  • Consensus clustering: patient subgroups from aggregated single-cell features.

Example use cases
  • T-cell proportions in responders vs. non-responders (boxplot)

  • Dotplot of checkpoint genes (PDCD1, CTLA4, LAG3) across immune populations

  • Tumour-immune ligand-receptor crosstalk with CellPhoneDB scoring

  • Malignant subclone identification with InferCNV

  • IFN-gamma signature activity in CD8+ T cells with ssGSEA

  • Pseudobulk differential expression in macrophages between tumour stages

Spatial transcriptomics

Spatial transcriptomics preserves tissue architecture while measuring expression, enabling study of cellular niches and the tumour microenvironment in situ.

  • Spatial slide display: Visium spots on tissue sections, coloured by metadata, gene expression, deconvolution results, or colocalization.

  • Spatial deconvolution: cell-type composition estimated per spot, displayed as pie charts overlaid on the tissue.

  • Gene-gene colocalization: spatial co-occurrence of two genes, identifying regions of coordinated expression.

  • Gene-cell type colocalization: where a gene's expression spatially overlaps deconvolved cell-type abundance.

  • Spatial InferCNV: copy-number variation inferred by comparing tumour against normal regions defined by spatial annotation.

  • Sparse aggregation, proportion, co-expression, and correlation: as for single-cell, computed per spatial region or tissue compartment.

Example use cases
  • Tumour microenvironment map: slide coloured by deconvolved immune composition

  • CD8A expression across tumour and stroma regions

  • Immune-tumour interface: colocalization of CXCL9 with T-cell abundance

  • Cell-type proportions in tumour core vs. invasive margin

  • PD-L1/PD-1 signalling at tumour-immune boundaries

  • Spatially distinct malignant clones with spatial InferCNV

Single-cell compared with spatial

Single-cell RNA-seq
Spatial transcriptomics

Resolution

Individual cells

~1-10 cells per spot

Tissue context

Dissociated (lost)

Preserved architecture

Key insight

Cell identity and states

Spatial organisation and niches

Deconvolution

Not required

Required for cell-type inference

Unique analyses

Trajectory inference

Colocalization, region comparison

H&E histomics

Histomics applies deep learning to whole-slide images, extracting quantitative features from standard pathology slides.

  • Cell-type density proportions: proportions of AI-detected cell densities — tumour cells, lymphocytes, fibroblasts, macrophages — compared across clinical groups.

  • Aggregation analysis: distributions of histomics features (cell densities, morphological metrics, spatial features) across groups.

  • Correlation analysis: between histomics features, or between histomics and molecular features, linking morphological and molecular phenotypes.

  • Survival analysis: Cox modelling and Kaplan-Meier curves stratified by histomics features such as high vs. low tumour-infiltrating lymphocyte (TIL) density.

  • Multivariate prognostic models: histomics features combined with clinical variables and molecular markers, assessing independent prognostic value.

  • Complex heatmap: clustered heatmaps of histomics features annotated by clinical variables or molecular subtypes.

  • Clustering and feature extraction: morphologically-defined subtypes, and minimal interpretable feature panels.

Feature categories

Category
Examples

Cell densities

Tumour cell, lymphocyte, fibroblast, macrophage density

Cell proportions

TIL proportion, stromal proportion, tumour proportion

Morphological features

Nuclear size, nuclear shape, pleomorphism

Spatial features

Cell clustering, spatial heterogeneity, tumour-stroma interface

Tissue architecture

Gland formation, necrosis fraction, inflammatory infiltrate patterns

Pathology Explorer

A dedicated module adds slide-level and tile-level capabilities: thumbnail display and an interactive pan-and-zoom viewer; filtering slides or tiles by any histomics feature; cohort feature statistics; AI model predictions overlaid on tiles; Kaplan-Meier analysis stratified by histomics feature; and export to Parquet.

Example use cases
  • Tumour-infiltrating lymphocyte density by treatment response (boxplot)

  • Cell-type composition across tumour stages (stacked bar)

  • Kaplan-Meier curves for high vs. low lymphocyte density

  • Cox model combining TIL density, CD8A expression, and stage

  • Slides with the highest lymphocyte density, then the tiles with the highest immune infiltration

  • Minimal histomics panel distinguishing responders, via feature extraction

  • CD8+ T-cell density on H&E correlated with CD8A bulk expression

Clinical variables

Clinical data gives molecular findings their context, supporting survival modelling, cohort characterisation, and treatment response analysis.

  • Clinico-pathological characterization: descriptive "Table 1" statistics — mean (SD) or median [IQR] for continuous variables, n (%) for categorical — with between-group hypothesis testing.

  • Survival and Kaplan-Meier analysis: Cox modelling and stratified curves for clinical variables such as stage, treatment, or biomarker status.

  • Timeline analysis: per-patient treatment histories, including therapy sequences, durations, and responses.

  • Treatment flow diagrams: patient flow across treatment sequences, such as 1L to 2L to 3L transitions.

  • Trajectory analysis: longitudinal measurements over time, such as tumour size, PSA, or biomarkers.

  • Population overview: patient count matrices by condition and dataset, for quick availability assessment.

  • Multi-variable and indication summaries: value distributions of several variables per group, and per-indication summaries of the relevant features.

  • Consensus clustering and feature extraction: patient subgroups and minimal actionable feature sets from clinical numerics.

Timeline, treatment flow, and trajectory analyses need treatment and measurement event data, which MOSAIC provides.

Variable types

Type
Examples
Typical analyses

Categorical

Gender, stage, grade, histology

Frequency tables, chi-square, stratified survival

Continuous

Age, BMI, tumour size, lab values

Mean/median comparison, t-tests, correlation

Time-to-event

OS, PFS, DFS

Kaplan-Meier, Cox regression, log-rank

Longitudinal

Treatment sequences, measurement trajectories

Timelines, flow diagrams, trajectory plots

Ordinal

ECOG status, tumour grade, line of therapy

Trend tests, stratified analyses

Example use cases
  • Table 1 comparing age, gender, and stage between responders and non-responders

  • Kaplan-Meier curves stratified by tumour stage

  • Multivariate Cox forest plot of age, stage, and grade effects on OS

  • Per-patient therapy sequences as a Gantt chart

  • 1L to 2L to 3L therapy transitions as a Sankey diagram

  • PSA or tumour size tracked over the course of treatment

  • Data completeness: summary table of missingness rates

Multimodal integration

Combining modalities is where K-Pro's analytical range matters most, supporting cross-platform validation and robust biomarker development.

Cross-modality concordance

Bulk RNA-seq can be compared against single-cell, spatial, or proteomics data; single-cell against spatial; and histomics against either expression or single-cell composition. These comparisons validate findings across platforms — for example confirming that a bulk expression signal localises to the expected tissue compartment, or that H&E-derived TIL density agrees with CD8A expression.

Integration analyses

  • Expression by mutation or CNV status: transcriptional programs associated with an alteration, and dosage-sensitive genes.

  • Transcriptomics with histomics: expression correlated against cell densities, expression stratified by histomics-defined groups, and joint clustering.

  • Proteomics with transcriptomics: protein-RNA correlation, differential expression concordance, and multi-omics clustering.

  • Single-cell with spatial: deconvolution validation, ligand-receptor analysis under spatial proximity constraints, and signature mapping onto spatial coordinates.

  • Clinical with molecular: Table 1 across molecularly-defined groups, survival by molecular subtype, covariate-adjusted molecular effects, and treatment response by biomarker.

  • Advanced: consensus clustering, feature extraction, and multivariate prognostic models over mixed features from several modalities at once.

Example use cases
  • Patient clustering on bulk RNA signatures, histomics densities, and clinical numerics together

  • Minimal gene + histomics + clinical panel per subtype, via feature extraction

  • Protein-RNA concordance to validate a transcriptomic biomarker at protein level

  • Multivariate survival model with age, stage, TP53 mutation, CD8A expression, and TIL density

  • Pathway activity in KRAS-mutant vs. wild-type patients

  • Genes with copy-number-driven expression

  • Response biomarker discovery combining differential expression, mutation enrichment, cell-type composition, and histomics features

  • Treatment timeline coloured by molecular subtype

Statistical methods

Method
Application

DESeq2

Negative binomial model for count-based differential expression

Welch's t-test

Two-group comparison for normalized expression

Wilcoxon rank-sum

Non-parametric two-group comparison, for example of histomics features

Pearson / Spearman

Pairwise correlation between features

Cox proportional hazards

Multivariate survival modelling

Kaplan-Meier estimation

Survival probability curves

Log-rank test

Survival curve comparison between groups

Chi-square / Fisher's exact

Categorical variable comparison

ANOVA / Kruskal-Wallis

Multi-group comparison

ssGSEA

Per-sample pathway enrichment scoring

GSEA

Ranked list enrichment against gene sets

Consensus clustering

Robust unsupervised patient subtyping

Elastic-net / OMP

Sparse feature selection for biomarker discovery

LIANA

Ligand-receptor inference for cell-cell communication

InferCNV

Copy-number inference from expression data

Dataset coverage by modality

Which analyses you can run depends on the modalities present in your dataset. Availability varies by plan and by data access agreement — see Browse the dataset catalog and What's included in your plan.

Dataset
Primary focus
Modalities

MOSAIC

Multi-indication oncology

Bulk RNA, single-cell, spatial, WES, histomics, clinical

TCGA

Pan-cancer atlas

Bulk RNA, WES, histomics, clinical

CPTAC

Proteogenomics

Bulk RNA, proteomics, WES (variants), clinical

GTEx

Normal tissue

Bulk RNA, clinical

CellxGene Breast

Breast cancer

Single-cell, clinical

CellxGene HNSCC

Head and neck cancer

Single-cell, clinical

CellxGene NSCLC

Lung cancer

Single-cell, clinical

CellxGene Intestinal

GI tract

Single-cell, clinical

MOSAIC offers the broadest multimodal coverage and is the only dataset supporting spatial transcriptomics.

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