CD19 and acute lymphoblastic leukemia: The success of anti-CD19 CAR-T cells in clinical trials prompted the approval of two second generation CAR-T cells products, tisagenlecleucel (2017) and axicabtagene ciloleucel (2018), by the US FDA for the treatment of pediatric and young adult patients with relapsed or refractory B cell acute lymphoblastic leukemia (B-ALL) (17) and adult patients with relapsed or refractory large B cell lymphomas (18), respectively.