BCL2L1 and Thrombocytopenia: It is important to note that thrombocytopenia is a dose-limiting toxicity of navitoclax caused by the induction of apoptosis in platelets, the survival of which is largely dependent on Bcl-xL.48,49 In the present study, the combination of navitoclax, gemcitabine, and IR induced thrombocytopenia, but did not cause adverse effects such as hemorrhagic diathesis, weight loss, and death (Supplementary Figure S12).