Fig. 1

a-c Fig. 1a shows the number of tumors (mean and s. e.: Total, SI-small intestine, LI-large intestine) counted at 15 weeks in female APC^min mice exposed to varying target doses from 7–15 weeks of age, and receiving up to 250 mg/kg PFOS in their drinking water. Controls received 0.5% Tween-20 vehicle only. Figure 1b shows the number of tumors counted by region (mean and s. e.: Total, SI-small intestine, LI-large intestine) in male APC^min mice exposed to target doses of up to 200 mg/kg PFOS in their drinking water. Figure 1c. The number of large tumors 1–3 mm in diameter plotted against PFOS is depicted. These results suggest PFOS may cause tumor regression, and not just prevent tumor development (mean and s. e.: Total, SI-small intestine, LI-large intestine). For the female study, animal numbers were 7, 8, and 4 for vehicle, 20, and 250 mg/kg dose groups respectively. For the male study, animal numbers were n = 6 for each group. Values represent total tumors counted in the vehicle controls as compared to each treatment group