BCL2L1 and Thrombocytopenia: Venetoclax was developed through rational design approaches as a high-affinity antagonist for Bcl-2 (with a Ki < 0.010 nM) and a 4000 fold lower affinity binding for Bcl-xL, to help overcome thrombocytopenia side effects derived from off-target Bcl-xL inhibition, and a common feature associated with ABT-737 and Navitoclax treatments [62].