CD274 and head and neck cancer: Indeed, PD-L1–CAR ha (high affinity) NK cells were already shown by others to be effective and safe in the treatment of immunodeficient mice bearing human head and neck cancer xenograft tumors,7 as well as triple-negative breast cancer (TNBC), lung or bladder tumors.23 However, the results presented in current work, as presented in figure 5C, indicate that the pattern of cytokines produced by target-activated CAR–NK-92 can be still sufficient for induction of PD-L1 on the target and bystander cells.