ERBB2 and ovarian mucinous adenocarcinoma: ERBB2 amplification is identified in up to 6.6% of all ovarian epithelial carcinomas (Tuefferd et al., 2007) and is more commonly seen (18 to 26%) in mucinous ovarian carcinomas (Mackenzie et al., 2015, Cheasley et al., 2019, Anglesio et al., 2013, Gorringe et al., 2020, McAlpine et al., 2009).