ABT-737 is a biphenyl compound, specifically 4-chloro-1,1'-biphenyl substituted with a (4-{4-[(4-{[(2R)-4-(dimethylamino)-1-(phenylsulfanyl)butan-2-yl]amino}-3-nitrobenzene-1-sulfonyl)carbamoyl]phenyl}piperazin-1-yl)methyl group at position 2'. It is a BH3-mimetic drug that targets anti-apoptotic BCL-2 family proteins, including BCL-2, BCL-xL, and BCL-w, inducing apoptosis in cancer cells. It functions as an anti-allergic, anti-inflammatory, antineoplastic, apoptosis-inducing, and BCL-2 inhibitor agent. It belongs to biphenyls, monochlorobenzenes, C-nitro compounds, aromatic amines, N-arylpiperazines, N-sulfonylcarboxamides, aryl sulfides, secondary amino compounds, and tertiary amino compounds.