CD19 CAR-T cells, which target conservatively and extensively expressed CD19 in B-cell lymphomas or leukemias74–76, have shown promising outcomes in several trials for treating relapsed, refractory B cell (R/R) cancers28,77–79, leading the U.S. Food and Drug Administration (FDA) to approve the first CAR-T cell product, tisagenlecleucel (Kymriah or CTL019), for the treatment of acute lymphoblastic leukemia (ALL) in children and adults80. The gene discussed is CD19; the disease is acute lymphoblastic leukemia.