biostudies-literatureUnknown644(8075)Chen AXYThe efficacy of chimeric antigen receptor (CAR) T cell therapy in solid tumours is limited by immunosuppression and antigen heterogeneity^1-3. To overcome these barriers, 'armoured' CAR T cells, which secrete proinflammatory cytokines, have been developed⁴. However, their clinical application has been limited because of toxicity related to peripheral expression of the armouring transgene⁵. Here, we have developed a CRISPR knock-in strategy that leverages the regulatory mechanisms of endogenous genes to drive transgene expression in a tumour-localized manner. By screening endogenous genes with tumour-restricted expression, we have identified the NR4A2 and RGS16 promoters as promising candidates to support the delivery of cytokines such as IL-12 and IL-2 direcNature241-251https://www.ebi.ac.uk/biostudies/studies/S-EPMC12328239biostudies-literatureRewiring endogenous genes in CAR T cells for tumour-restricted payload delivery.PMC12328239Lai JWaithman JHarrison SJWiebking VPorteus MHYap KMMunoz IHuang YKArmitage JDMiddelburg JLee JNParish IATong JHoang TXvan Elsas MJMackay LKBeavis PAChan CWScott AMTodd KLLi JSek KAudsley KMOliaro JHouse IGKim JSDarcy PKDunbar PADerrick EBScheffler CNguyen DCole TJde Menezes MNChen AXYfalseRewiring endogenous genes in CAR T cells for tumour-restricted payload delivery.The efficacy of chimeric antigen receptor (CAR) T cell therapy in solid tumours is limited by immunosuppression and antigen heterogeneity^1-3. To overcome these barriers, 'armoured' CAR T cells, which secrete proinflammatory cytokines, have been developed⁴. However, their clinical application has been limited because of toxicity related to peripheral expression of the armouring transgene⁵. Here, we have developed a CRISPR knock-in strategy that leverages the regulatory mechanisms of endogenous genes to drive transgene expression in a tumour-localized manner. By screening endogenous genes with tumour-restricted expression, we have identified the NR4A2 and RGS16 promoters as promising candidates to support the delivery of cytokines such as IL-12 and IL-2 direc2025-01-01T00:00:00Z2025 Aug2026-04-13T08:17:01.979Z2026-04-07T13:29:27.673ZS-EPMC123282394060428510.1038/s41586-025-09212-7