CD19 and lymphoma: Moreover, researchers disrupted the TRAC gene to avoid graft-versus-host reactions.458 To further improve the efficacy of CAR T cells, alemtuzumab, a chemotherapeutic agent, was administered to downregulate CD52 genes and synergistically promote engraftment by mediating lymphodepletion and immunosuppression, and it endowed TCR/CD52-deficient CD19 CAR T cells (dKO-CART19) with potent antitumor activity in an orthotopic CD19+ lymphoma murine model.458 Recently, the CRISPR/Cas system has emerged as a potential genome engineering tool for CAR T cell therapy.