BCL2 and B-cell chronic lymphocytic leukemia: Antagonists targeting BCL‐2/BCL‐XL (ABT‐737 and ABT‐263/navitoclax) or BCL‐2 only (ABT‐199/GDC‐0199/venetoclax) have shown clinical benefit, notably leading to the recent regulatory approval of venetoclax in CLL and AML.