CD19 and acute lymphoblastic leukemia: Genetically-engineered UCB-derived T-cells (CD19-CAR-T) or UCB-derived NK cells (CD19-CAR-NK) have shown cytolytic activity in vitro and in vivo, in models of B-lineage acute lymphoblastic leukemia (B-ALL) or in patients with relapsed or refractory B-cell hematologic malignancies [48,49].