APP and breast carcinoma: Moreover, the overexpression of APP in MDA-MB-231 cells increased levels of mesenchymal markers, including MMP-9, MMP-2, MMP3, N-cadherin, and vimentin, but decreased those of epidermal-associated markers, including cytokeratin, which implies APP overexpression in association with the mitogen-activated protein kinase (MAPK) signaling pathway is implicated in breast cancer invasiveness and metastasis [28].