CD19 and cancer: After prolonged cancer cell antigen exposure, autocrine scFv PD-L1 antibody promoted the proliferation ability, cytotoxicity, and IL-2 and IFN-γ secretion of CD19.BBz.PD-L1 and Her2.BBz.PD-L1 CAR T cells, suggesting that autocrine scFv PD-L1 antibody can improve T cell functions.