# CD39 (ENTPD1)

Source: https://onco.cc/targets/entpd1/  
OnCo record `entpd1` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

CD39 is the first of two enzymes that turn the ATP spilt by dying tumour cells into adenosine, which sedates T cells. Blocking it keeps the ATP alarm ringing; one antibody has completed phase 2 in pancreatic cancer.

## Summary

ENTPD1 (chromosome 10q24.1) catalyses the hydrolysis of nucleoside triphosphates and diphosphates, sequentially removing phosphate groups to leave nucleoside monophosphates; it is expressed primarily on activated lymphoid cells and in endothelium, and highly in placenta, lung, skeletal muscle and kidney (UniProt P49961). CD39 and CD73 together catabolise extracellular ATP into adenosine, and both, with adenosine receptors, have emerged as therapeutic targets (Allard et al. 2019, Immunol Rev). TTX-030, an anti-CD39 antibody, completed a phase 2 study with chemotherapy, with or without budigalimab, in first-line metastatic pancreatic cancer (NCT06119217).

## Fields

- Kind: Target
- Last checked: 2026-09-24
- Also known as: CD39; NTPDase-1; ectonucleoside triphosphate diphosphohydrolase 1
- Tags: checkpoint-map
- Symbol: ENTPD1
- Class: enzyme
- Biology: The upstream ectonucleotidase of the adenosine axis; CD73 (NT5E) finishes the conversion.
- Where found: Activated lymphoid cells, endothelium (UniProt P49961); Pancreatic cancer trial of TTX-030 (NCT06119217)

## Notes

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

## Sources

- HGNC HGNC:3363: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:3363
- UniProt P49961: https://www.uniprot.org/uniprotkb/P49961/entry
- NCBI Gene 953: https://www.ncbi.nlm.nih.gov/gene/953
- ClinicalTrials.gov NCT06119217: https://clinicaltrials.gov/study/NCT06119217

## Connected records

- targets: [Adenosine A2A receptor (ADORA2A)](https://onco.cc/targets/adora2a/), [CD73 / adenosine axis](https://onco.cc/targets/cd73-adenosine/)
- cancers: [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/entpd1.json