Comparison of in vivo activity of apogossypol and gossypol in Bcl-2–transgenic mice. Pairs of age-matched (starting ages ranged from 39 to 73 weeks), sex-matched Bcl-2–transgenic mice were orally administered vehicle control (C) and either apogossypol (A) or gossypol (G), at either 60 μmol/kg or 120 μmol/kg (as indicated), 5 times weekly for 3 weeks. At conclusion of treatment, mice were killed and spleens removed and weighed (top), then splenocytes were isolated and analyzed by FACS to determine the number of B cells, typically using either B220 or CD19 as B-cell markers (bottom).