It is important to note, however, that cyclin E1 protein overexpression itself has not been shown to be a predictive biomarker for chemotherapy resistance in epithelial ovarian cancer (EOC), so methods to detect amplification of a gene (e.g. whole-genome sequencing, fluorescence in situ hybridization, polymerase chain reaction, single nucleotide polymorphism arrays) are required to identify the CCNE1 amplified subgroup (69). This evidence concerns the gene CCNE1 and ovarian carcinoma.