CD19 and neoplasm: For instance, clinical outcomes from anti-CD19 CAR-T cells demonstrate that inclusion of the CD28 or 4-1BB costimulatory domain enables CAR-T cell long persistence, enhanced cytotoxicity, and a safer profile.23, 24, 25 Thus, costimulatory domains associating with the KIRS2/Dap12 receptor may enhance anti-tumor efficacy of T cells.