Many factors, including expression of epidermal growth factor (EGF), hepatocyte growth factor (HGF) and insulin-like growth factor, have been demonstrated to correlate well with the invasiveness or metastasis potential of these cancers; these seem to be associated in breast cancer cells with phosphatidylinositol 3-kinase (PI3K) or MAPK (ERK or p38) activation together with COX2 overexpression. This evidence concerns the gene MAPK1 and breast cancer.