HER2-overexpression represents a poor prognostic marker in multiple tumors, including ovarian cancer, where it is associated with chemoresistance, poor OS (HR = 1.57, 95%CI = 1.31 to 1.89), and decreased PFS (HR 1.26, 95%CI = 1.06 to 1.49) [44]. This evidence concerns the gene ERBB2 and ovarian cancer.