To date, five different CAR T-cell products have been approved by the US Food and Drug Administration (FDA), including four products targeting CD19 for acute lymphocyte leukemia (ALL) or lymphoma [1–4] and idecabtagene vicleucel (Abecma) targeting B cell maturation antigen (BCMA), which has recently been approved for relapsed or refractory multiple myeloma (R/R MM) [5]. The gene discussed is TNFRSF17; the disease is acute lymphoblastic leukemia.