We cultured human PC-3 prostate cancer cells in growth factor defined (epidermal growth factor [EGF] and fibroblast growth factor [FGF]-2) serum-free medium for the enrichment of PCSCs and detected the stem cell markers including Notch-1, Oct-4, and Nanog in PCSCs and parental cells. The gene discussed is NANOG; the disease is prostate cancer.