CD19 and neoplasm: Using a xenograft lymphoma mouse model, similar results were obtained for the in vivo effector function of these CAR‐T cells where a DKO and TKO was induced, leading to a significant reduction in tumor size, indicating that the CRISPR‐mediated multiplex gene deletion of HLA‐1 and TCR from CAR‐T cells retained their CD19‐specific antitumor function.60