# Reverse-phase protein array (RPPA)

Source: https://onco.cc/terms/rppa/  
OnCo record `rppa` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

RPPA spots tiny amounts of protein extract from many tumours onto a slide and probes them with antibodies, measuring a few hundred proteins and phosphoproteins in each sample at once.

## Summary

A reverse phase protein lysate microarray is a dot-blot platform that measures protein expression in many samples simultaneously and quantitatively where high-quality antibodies exist (Wikipedia). TCGA ran RPPA on most tumours for roughly 150 to 200 proteins and phosphoproteins chosen for signalling pathways, which makes it the only pan-cancer protein data at scale, though a targeted rather than genome-wide view. Deep mass spectrometry from CPTAC covers thousands of proteins on fewer tumours.

## Fields

- Kind: Term
- Last checked: 2026-09-24
- Also known as: RPPA; reverse-phase protein array; reverse phase protein array; protein array data; RPPA data
- Tags: cansim-terms

## Notes

- Listed in the CanSim terms map 1.0.0 (docs/onco/terms.json, generated 2026-09-24), CC BY 4.0, attribution: CanSim project, an open, public-data-first cancer foundation-model programme; CanSim page path /terms/rppa.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Reverse_phase_protein_lysate_microarray
- Wikipedia: https://en.wikipedia.org/wiki/Reverse_phase_protein_lysate_microarray

## Connected records

- collections: [TCGA / NCI Genomic Data Commons](https://onco.cc/collections/tcga-gdc/)
- terms: [Cancer AI vocabulary (CanSim terms map)](https://onco.cc/terms/cancer-ai-vocabulary/), [Deep mass-spectrometry proteome (CPTAC)](https://onco.cc/terms/mass-spec-proteome/), [Pathway activation state (phosphosignalling)](https://onco.cc/terms/pathway-activation-state/)
- technologies: [Proteomics & phosphoproteomics](https://onco.cc/technologies/proteomics/)

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JSON: https://onco.cc/api/v1/entities/rppa.json