In the aforementioned clinical trial of anti-CD19 CAR-T cells as a treatment for CLL/SLL, an MRD-CR rate of 60% was obtained in 30 days at doses of 50 × 10e6 and 100 × 10e6; however, the anti-CD19 4-1BB-armored CAR-T cell trial administered only 5 × 10e6 CAR-T cells per patient. This evidence concerns the gene CD19 and B-cell chronic lymphocytic leukemia.