In conclusion, the results from the current study showed that 1) endometrial estrogen receptors, which can be carcinogenic, were present in higher levels with diabetes and that exercise training showed a trend to reverse it; 2) levels of p16, a known tumor suppressor, were decreased with diabetes, but reversed when the diabetic animals exercised; 3) endometrial hyperplasia was noted in 70% of the samples from the sedentary diabetic rats, but not in the exercise trained animals. This evidence concerns the gene ESR1 and diabetes mellitus.