CASP9 and B-cell chronic lymphocytic leukemia: The study’s evidence that pharmacological inhibition of survivin (BIRC5)—a protein that directly blocks caspase 9 activation [79-82] with a separate role in promoting cell mitosis [81,83]—is effective at both inducing apoptosis and blocking further CLL divisions suggests that survivin inhibitors could be a beneficial adjunct with venetoclax.