LEP and breast cancer: According to their results, proliferation, migration, and invasion in breast cancer are all affected by both agonists (IL-1, leptin) and antagonists (IL-1ra, adiponectin) expressed in mammary adipose cells acting through specific receptors in both an autocrine and a paracrine way on mammary tumour cells, regulating the production of growth factors and epithelial-derived and angiogenic proteins, stimulating the invasion and proliferation of other cancer cells [8].