CD19 and B-cell acute lymphoblastic leukemia: CD19 CAR T cell therapy has shown remarkable clinical efficacy in multiple subtypes of B cell lymphoma (20) and led to the US Food and Drug Administration approval of two CD19 CAR products for relapsed or refractory B-cell acute lymphoblastic leukemia and aggressive non-Hodgkin lymphoma treatment (21, 22, 23, 24).