Effect of estrogens or IL-6 on tamoxifen-induced apoptosis of S6B45 MM cells. S6B45 MM cells were cultured for 72 hours in media alone or with TAM (5.0 μmol/L), E2 (50 μmol/L), or both (A). These cells were also cultured for 72 hours in media alone, IL-6 (1 ng/mL), TAM (0.5 μmol/L), DEX (0.5 μmol/L), and either TAM or DEX with IL-6 (B). Apoptosis was determined by PI staining and FACS analysis. The percentages of cells within the apoptosis gate are shown.