A potent, small molecule Bcl-2 family protein inhibitor (Ki's of <1 nmol/L for Bcl-2, Bcl-XL and Bcl-w). Displays anticancer properties. Selectively binds to apoptosis suppressor proteins Bcl-2, Bcl-XL, and Bcl-w and prevents their binding to the apoptotic effectors Bax and Bak proteins, which may trigger apoptosis in tumor cells overexpressing Bcl-2, Bcl-XL, and Bcl-w. MW: 974.61. Purity ≥98% by HPLC