The patient responded to trastuzumab monotherapy and combination therapy with Iapatinib with stable disease for approximately 9 months, evident with a downtrend in the serum marker CEA and improvement in Eastern Cooperative Oncology Group (ECOG) performance status.21 Furthermore, in a second case report of a patient with mucinous ovarian carcinoma pre-treated with chemotherapy and bevacizumab, the patient was switched to chemotherapy and trastuzumab after detecting a strong ERBB2 gene amplification. Here, ERBB2 is linked to ovarian mucinous adenocarcinoma.