# CD69

Source: https://onco.cc/targets/cd69/  
OnCo record `cd69` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

CD69 appears within hours of a lymphocyte being activated, so it is the quickest way to tell that something has just woken the immune system up. It also keeps T cells inside a tissue rather than letting them drift back to the blood.

## Summary

CD69 is the earliest surface antigen induced after lymphocyte activation, appearing within hours, which makes it the standard readout for a response that has just happened rather than one that happened weeks ago. It has a second job: by opposing sphingosine-1-phosphate receptor 1 it keeps cells from leaving a tissue, and so it is one of the markers that define tissue-resident memory T cells, the population that stays inside an organ, including inside a tumour.

## Fields

- Kind: Target
- Last checked: 2026-10-16
- Tags: immune-marker
- Symbol: CD69
- Class: surface-antigen
- Biology: Earliest inducible surface antigen after lymphocyte activation; also retains cells in tissue by opposing S1P receptor 1.
- Where found: Recently activated lymphocytes; Tissue-resident memory T cells

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/CD69
- HGNC:1694: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:1694

## Connected records

- targets: [CD25 (IL-2 receptor alpha)](https://onco.cc/targets/cd25/), [CD62L](https://onco.cc/targets/cd62l/)
- terms: [T cell](https://onco.cc/terms/t-cell/), [T-cell exhaustion and CAR-T persistence](https://onco.cc/terms/t-cell-exhaustion-term/)

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JSON: https://onco.cc/api/v1/entities/cd69.json