BCL2 and Thrombocytopenia: As the first highly selective Bcl-2 inhibitor for clinical use, VEN has an over three orders of magnitude affinity for Bcl-2 than Bcl- XL and Bcl-W [10], which can greatly improve the problem of dose-dependent thrombocytopenia caused by low selective Bcl-2 inhibitors acting on Bcl- XL [7,40,41].