In most of the reported studies, NOD or severe combined immune deficiency (SCID) or NOD/SCID/γ-chain−/− mouse xenograft tumor model was used to evaluate the efficacy of CAR-T cell treatment alone (37, 38) or in combination of PD1 blockage (27, 28, 30). The gene discussed is PDCD1; the disease is Immunodeficiency.