CD19 and acute lymphoblastic leukemia: The clinical successes with CAR T cell therapy has recently led to the FDA approval of two CD19 CAR therapies for ALL and NHL in 2017, namely axicabtagene ciloleucel (Yescarta) with costimulatory molecule CD28 and tisagenlecleucel (Kymriah) with costimulatory molecule 4-1BB [99].