Leptin activates a number of signalling pathways that have been previously described as important in cancer promoting events and that overlap with the induction of EMT, including MAPK and Wnt/β-catenin [26–28], however leptin signalling through the TGFB1 pathway, a major player in EMT, has not been demonstrated in breast cancer. This evidence concerns the gene TGFB1 and cancer.