CASP9 and B-cell chronic lymphocytic leukemia: Eleven heavily pretreated patients with CD19+ relapsed or refractory (r/r) chronic lymphocytic leukemia (CLL) or NHL were enrolled in the clinical trial; they received UCB-derived CAR-NK cells with a novel construct incorporating the IL-15 gene and an inducible caspase-9-based suicide gene after lymphodepleting chemotherapy.