Since VitD upregulates VDR expression [28,29,30], and VDR is known to repress autophagy in human breast cancer cells and in mice [26], we hypothesized that VitD can inhibit the pro-survival autophagy that is initiated by treating antiestrogen-resistant breast cancer cells with tamoxifen (TAM) [10,11]. The gene discussed is VDR; the disease is breast carcinoma.