MET and breast cancer: Over the years, a number of studies have described the participation of MET and ETS factors in various malignant tumours such as oesophageal cancer, lung cancer, melanoma, breast cancer and gastric cancer, and all refer to them as important in cancer progression and in particular as having a key role in cell proliferation, migration, invasion, apoptosis and the cell cycle [44, 46, 52, 53, 54].