EGF and cancer: It has been demonstrated that calcitriol/VDR in cancer cells activates cyclin-dependent kinase inhibitors, inhibits mitogenic growth factors (Epidermal growth factor (EGF) EGF, Insulin-like growth factor I (IGF-1), and increases transforming growth factor beta (TGF-β) activity, which stops cell proliferation and the growth of cancer (Table 1).