ERBB2 and ovarian serous adenocarcinoma: Unlike high-grade serous ovarian cancers (which often carry TP53 or homologous recombination defects), MOC typically features recurrent alterations in cell signaling genes—for example, activating mutations in the RAS–MAPK pathway (KRAS and BRAF) or overexpression/amplification of receptor tyrosine kinases like HER2/ERBB2.