CD4 and cancer: In the phase I study targeting NSCLC patients (NCT03215810), both CD8 and CD4 T cells capable of recognizing cancer‐testis antigens and neoantigens were found in TIL infusion products, and these cells were strongly associated with objective clinical response.[52, 68] This suggests that the greater the clonal diversity within TIL products, the more diverse the arsenal against tumor antigens, thereby increasing the likelihood of therapeutic response.