# Adenosine A2A receptor (ADORA2A)

Source: https://onco.cc/targets/adora2a/  
OnCo record `adora2a` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The A2A receptor is where adenosine lands on a T cell and tells it to rest. Oral antagonists, cousins of caffeine, are in phase 2 combinations with PD-1 blockade and chemotherapy.

## Summary

ADORA2A (chromosome 22q11.23) encodes a G-protein-coupled adenosine receptor whose activity is mediated by G proteins that activate adenylyl cyclase (UniProt P29274). Ectonucleotidases and adenosine receptors are broadly expressed and have emerged as immuno-oncology targets, with early-phase trials showing promising results (Allard et al. 2019, Immunol Rev). Ciforadenant is in phase 1b/2 with ipilimumab and nivolumab (NCT05501054), etrumadenant (A2A/A2B) in phase 2 combinations in pancreatic cancer (NCT06048484), and inupadenant in phase 2 with chemotherapy in non-squamous non-small-cell lung cancer (NCT05403385).

## Fields

- Kind: Target
- Last checked: 2026-09-24
- Also known as: A2AR; A2A receptor; adenosine A2a receptor; RDC8
- Tags: checkpoint-map
- Symbol: ADORA2A
- Class: surface-antigen
- Biology: The receptor end of the CD39-CD73-adenosine axis; antagonists are small molecules.
- Where found: Broadly expressed, per Allard et al. 2019; UniProt records no human tissue distribution; Pancreatic and non-small-cell lung cancer trials of antagonists

## Notes

- Prevalence not recorded: HGNC and UniProt carry no positivity rates.

## Sources

- HGNC HGNC:263: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:263
- UniProt P29274: https://www.uniprot.org/uniprotkb/P29274/entry
- NCBI Gene 135: https://www.ncbi.nlm.nih.gov/gene/135
- Allard et al. 2019, Immunol Rev (Europe PMC): https://europepmc.org/article/MED/29758241

## Connected records

- targets: [CD39 (ENTPD1)](https://onco.cc/targets/entpd1/), [CD73 / adenosine axis](https://onco.cc/targets/cd73-adenosine/)
- cancers: [Non-small-cell lung cancer](https://onco.cc/cancers/nsclc/), [Pancreatic ductal adenocarcinoma](https://onco.cc/cancers/pancreatic/)
- pathways: [The cancer-immunity cycle](https://onco.cc/pathways/cancer-immunity-cycle/)
- terms: [Checkpoint (two meanings)](https://onco.cc/terms/checkpoint/)

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JSON: https://onco.cc/api/v1/entities/adora2a.json