AR and prostate cancer: Basal epithelial cells separate the lumen from the stroma, express less AR and are positive for cytokeratins 5 and 14, p63 (prostate basal cell marker of some PCa subtypes [23]), CD44 (a cell-surface protein involved in glucose metabolism of prostate cancer cells [24]) and GSTP1 (belongs to glutathione S-transferases family; enzymes active in detoxification of exogenous substances; involved in the regulation of the cell cycle [25]) [18].