The production of EGF is regulated by androgens and the proliferation response of epithelial cells to androgens also requires the participation of EGF.[55] The α1 adrenoceptor mediated human hyperplastic prostate cells proliferation is impaired by EGF receptor inhibition.[56] In recurrent prostate cancer[57] and bladder cancer cells,[58] EGF can activate the AR signaling pathway and promote the proliferation of tumor cells. This evidence concerns the gene AR and urinary bladder cancer.