BCL2L1 and Thrombocytopenia: The evolution of BH3 mimetics has gone from first-generation experimental agents targeting Bcl-2 and Bcl-XL, used primarily in mouse models (ABT-737), to formulations optimized for oral administration (ABT-263, Navitoclax; highly binds Bcl-2, Bcl-XL, Bcl-w), to second-generation agents that are more precise in binding only Bcl-2 (ABT-199, Venetoclax) and sparing Bcl-XL and consequent effects on platelet survival and thrombocytopenia.