MAPK3 and breast cancer: http://en.wikipedia.org/wiki/HER2/neu - cite_note-3Inhibition of ErbB2 tyrosine autophosphorylation by lapatinib abrogates downstream Ras-Raf-ERK1/2 and PI3K-AKT growth/survival signaling in ErbB2 overexpressing breast cancer cell lines and in patients with ErbB2-overexpressing breast cancers [14].