# CD28

Source: https://onco.cc/targets/cd28/  
OnCo record `cd28` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

CD28 is the second signal a T cell needs before it attacks. Many CAR-T cells carry a piece of CD28 inside them to fire harder, ipilimumab works by stopping CTLA-4 from hogging CD28's partners, and a new bispecific antibody presses CD28 directly on T cells that are already bound to prostate cancer cells.

## Summary

CD28 (chromosome 2q33.2) is the T-cell receptor for CD80 and CD86 that drives T-cell activation, proliferation and survival: it amplifies T-cell receptor signals and delivers its own, recruiting PKC-theta and GRB2 to activate NF-kappa-B through PI3K/AKT-dependent and independent routes and raising proliferation and IL-2 production in CD4 and CD8 T cells (UniProt P10747). In OnCo it appears three ways: as the costimulatory domain built into the CD19 CAR-T products axicabtagene and brexucabtagene (the lisocabtagene record notes slower expansion and less CRS and ICANS than CD28-based products); as the receptor CTLA-4 outcompetes for B7 ligands, the priming step ipilimumab releases; and as the T-cell arm of JNJ-87189401, a PSMA x CD28 costimulatory bispecific in phase 3 for prostate cancer.

## Fields

- Kind: Target
- Last checked: 2026-09-22
- Also known as: CD28 molecule; CD28 costimulatory receptor
- Tags: wave5-target
- Symbol: CD28
- Class: surface-antigen
- Biology: CD28 is constitutively expressed on T cells, and CD80 on antigen-presenting cells is its primary auxiliary signal (UniProt P33681). The bispecific approach costimulates only T cells whose other arm is already engaged with a tumour antigen, here PSMA.
- Where found: T cells (constitutive); the costimulatory domain of CD19 CAR-T products; Prostate cancer (PSMA x CD28 bispecific JNJ-87189401)

## Notes

- Prevalence not recorded in this wave: HGNC and UniProt carry no positivity rates and no other source was consulted.

## Sources

- HGNC HGNC:1653: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:1653
- UniProt P10747: https://www.uniprot.org/uniprotkb/P10747/entry
- NCBI Gene 940: https://www.ncbi.nlm.nih.gov/gene/940

## Connected records

- drugs: [Axicabtagene ciloleucel](https://onco.cc/drugs/axicabtagene-ciloleucel/), [Brexucabtagene autoleucel](https://onco.cc/drugs/brexucabtagene-autoleucel/), [Ipilimumab](https://onco.cc/drugs/ipilimumab/), [JNJ-87189401](https://onco.cc/drugs/jnj-87189401/), [Lisocabtagene maraleucel](https://onco.cc/drugs/lisocabtagene-maraleucel/)
- targets: [CD137 (4-1BB, TNFRSF9)](https://onco.cc/targets/cd137/), [CD80 (B7-1)](https://onco.cc/targets/cd80/), [CTLA-4](https://onco.cc/targets/ctla4/), [PSMA](https://onco.cc/targets/psma/)
- cancers: [Diffuse large B-cell lymphoma](https://onco.cc/cancers/dlbcl/), [Prostate cancer](https://onco.cc/cancers/prostate/)
- technologies: [Bispecific antibodies](https://onco.cc/technologies/bispecific-antibody/), [CAR-T cell therapy](https://onco.cc/technologies/car-t/)
- pathways: [PD-1 / PD-L1 immune checkpoint & T-cell activation](https://onco.cc/pathways/pd1-checkpoint/), [The cancer-immunity cycle](https://onco.cc/pathways/cancer-immunity-cycle/)

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JSON: https://onco.cc/api/v1/entities/cd28.json