In addition, leptin promotes epithelial-to-mesenchymal transition (EMT) [39] by up-regulating the expression of CSC/EMT-related genes [205], tumor evasion, cell migration [206,207], tumor size, overexpression of estrogen and progesterone receptors [208], protection of malignant cells from apoptosis [38], and breast cancer metastasis [209]. Here, LEP is linked to breast cancer.