CTAG1A and neoplasm: NY‐ESO‐1 has been targeted using an unmodified endogenous TCR from a HLA‐DPB1*04:01 (DPB1)‐restricted CD4+ T cell clone raised by IVS182 and gene engineering with an affinity‐enhanced HLA‐A2*01:01 (A2)‐restricted TCR.135, 136, 137, 138 Despite mediating cancer regression, including durable CRs, no evidence of off‐tumor toxicity was observed in these trials.