This was associated with increased cleavage of PARP and caspase-3 in sensitive KMT2A-r, but not in KMT2A-wt leukemia cells (Figure 3B and Supplementary Figure 4), indicating that the compound rapidly kills sensitive KMT2A-r leukemia cells through caspase-dependent apoptosis. Here, CASP3 is linked to leukemia.