Combination of selenium and sulindac impacted p21 promoter methylation in intestinal epithelial cells of Apc/p21+/− mice (A). “ Se” stands for AIN-76A+selenium; “ Se+Sul ” stands for AIN-76A+selenium +sulindac. B. Quantification of the MS-PCR band intensity in individual mouse. C, Overall average of the MS-PCR band intensity in each group. In AIN-76A and Se alone group, the methylation was higher than unmethylation (*p<0.05, compared to the unmethylation groups), but in Se + Sul groups, the methylation status was significantly reversed into unmethylation (**p<0.01, compared to the unmethylation groups).