Diethylstilbestrol (DES), a synthetic estrogen, was widely administered to pregnant women between 1947 and 1971 on account of a misconception that it could prevent miscarriages. The offspring of these women were diagnosed with various reproductive tract abnormalities, including cancer. We focused this study on DES-induced abnormalities in the uterus. We screened for altered DNA methylation patterns in uteri from control vs. neonatally DES-treated hamsters using MSRF. Preliminary results show differential DNA methylation patterns in uteri of control vs. DES-treated hamsters. Next we will determine the nucleotide sequence of the differentially methylated genetic elements.