Moderate activity of M3258 against KMT2A::AFF1 ALL in vivo has prompted us to ask whether it will be enhanced by inhibitors of the trypsin-like and the caspase-like sites, which were shown in our previous work to sensitize cells derived from various cancers to Btz, Cfz and ONX-091422,23,29–31,52. This evidence concerns the gene CASC3 and acute lymphoblastic leukemia.