EGFR and ovarian cancer: A recent study found that HE4 may play an important role in EGFR activation and the MAPK signaling pathway [12] in ovarian cancer cells, this result was further confirmed by findings that HE4 might inhibit cell proliferation by regulating MAPK and PI3K/AKT pathways in vitro [15] and HE4 was linked to the activity of EGF, VEGF, insulin and HIF1α [10].