Indeed, several studies have demonstrated that the disruption of PD-1 using CRISPR results in the enhanced anti-tumor activity of CAR-T cells (33, 55, 56), which was also partially observed in our in vitro and in vivo experiments with NY-ESO-1 T cells lacking PD-1 expression (NE1ΔPD-1 T cells). The gene discussed is PDCD1; the disease is neoplasm.