Existing data indicate that a variety of estrogen hormones, such as estradiol and progesterone, increase the expression level of VEGF in breast cancer (87, 88), while tamoxifen can inhibit the secretion of VEGF (89) and reduce the density of vascular endothelial cells in breast cancer by more than 50%, the mechanism of which is related to the regulation of the expression ratio of VEGF and sVEGFR-1 (90). This evidence concerns the gene VEGFA and breast cancer.