Another clinically advanced but currently unregistered BH3-mimetic is the predecessor molecule to venetoclax, the BCL2/BCL-XL/BCL-w inhibitor navitoclax (ABT-263), whose clinical efficacy in CLL/SLL was compromised by dose-limiting thrombocytopenia due to the reliance of platelets on BCL-XL for survival [15, 16]. The gene discussed is BCL2L1; the disease is B-cell chronic lymphocytic leukemia.