A low level of vitamin D, indicating a low level of 25-hydroxy vitamin D (25(OH)D), and low level of vitamin D receptor (VDR) in tumor tissue are recognized as risk factors of breast cancer and correlated with clinical parameters such as the incidence of breast cancer, tumor biology, prognosis, and treatment tolerance [1,2,3,4,5,6]. The gene discussed is VDR; the disease is breast carcinoma.