Once the presence of EpCAM positive CTCs in the blood of patients was confirmed using two methodologies, an expression profile analysis, including a panel of genes related to cell plasticity and ovarian cancer aggressiveness (MUC1, CK19, CXCR4, TIMP1, ALDH1, CD24, CD44, GDF1), was carried out. This evidence concerns the gene ALDH1A1 and ovarian cancer.