The University of Texas MD Anderson Cancer Center spearheaded a phase I/IIa clinical study (NCT03056339) to assess the safety and efficacy of cord blood-derived cluster of differentiation 19 (CD19)-targeted CAR-NK cells (designated CAR19/IL-15 NK cells) in patients with relapsed or refractory CD19-positive B-cell hematological malignancies, such as non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL). This evidence concerns the gene CD19 and B-cell chronic lymphocytic leukemia.