CD19 and precursor B-cell acute lymphoblastic leukemia: CD19 chimeric antigen receptor T-cell (CAR-T) therapy has resulted in an impressive, high clinical response rate among patients with refractory/relapsed (R/R) B-cell hematological malignancies, yielding about a 90% complete response (CR) rate in B-cell acute lymphocytic leukemia (B-ALL) and about a 50% CR rate in B-cell non-Hodgkin’s lymphoma (B-NHL) [1,2,3].