CD19 and leukemia: Most emblematically, CD19-CAR-T and CD19-CAR-NK, CARs with optimal co-stimulatory signaling and clinical efficacy, have provided an impetus for additional research in both cancer and infectious diseases [6, 7], showing demonstrated beneficial outcomes in patients with B cell lymphoma [8, 9] relapsed or refractory CD19-positive non-Hodgkin's lymphoma, and chronic lymphocytic leukemia [CLL]) [10], CAR-T cell immunotherapy has also shown promising results for multiple myeloma [11, 12], leukemia [9, 13–15], sarcoma [16], and neuroblastoma [17, 18].