MCL1 and cancer: To verify that XPO1 degradation upon KPT-330 contributes to Mcl-1 reduction and cancer cell apoptosis following KPT-330 and A-1331852 treatment, we reconstituted XPO1 expression by overexpressing wild-type XPO1, degradation-resistant mutant C528S, or recurrent hotspot mutant E571K or R749Q in U251 and H1299 cells.