Gemcitabine functionally inhibited DNA methyltransferase activity in both nuclear extract and recombinant protein, reactivating several epigenetically silenced genes, including GSTP1, IGFBP3, and RASSF1A. This compound also destabilized DNMT1 in PCa cell lines (LNCaP, 22Rv1 and DU145). The gene discussed is DNMT1; the disease is posterior cortical atrophy.