CD19 and acute lymphoblastic leukemia: Similar to the sequential infusion of anti-CD19 and anti-CD22 CAR-T cells in treating R/R acute lymphocytic leukemia (ALL) as well as B cell lymphoma, and combined infusion of CD19 and B cell mature antigen (BCMA)-specific CAR-T cells for R/R multiple myeloma, combining anti-CD19 with anti-CD23 CAR-T cells to treat R/R CLL might be a promising strategy as well.