CD19 and acute lymphoblastic leukemia: CAR-T cell products targeting the CD19 antigen have been approved for most B-cell malignancies, including relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL), diffuse large B-cell lymphoma (DLBCL), primary mediastinal large B-cell lymphoma (PMBCL), transformed follicular lymphoma, and mantle cell lymphoma, while two anti-BCMA CAR-T cell products have been approved for R/R multiple myeloma (MM).