BCL2 and colorectal cancer: First, anti-apoptotic Bcl-2 family members (Bcl-2, Bcl-xL, Mcl-1) are frequently overexpressed in gastric and colorectal cancers; by antagonizing Bax/Bak oligomerization and preserving mitochondrial integrity, they prevent cytochrome c release and caspase activation, thereby conferring resistance to 5-fluorouracil and oxaliplatin (38–40).