CD19 and Burkitt lymphoma: We also confirmed that iKP CAR could inhibit the CD19 CAR activation signal via the PD-1 domain and CD19-CAR-T cells bearing an iKP CAR (iKP-19-CAR-T) exerted robust cytotoxicity in vitro and antitumor activity in the xenograft model of CD19+HLA-C1− Burkitt’s lymphoma parallel to CD19-CAR-T cells, whilst sparing CD19+HLA-C1+ healthy human B cells both in vitro and in the xenograft model.