CD44 and ovarian serous adenocarcinoma: The newly established unique immortalized cell line OvCa7 A hTERT with a characteristic of serous ovarian cancer malignancy feature, with the accumulation of the p53 and Pax8, and the overexpression of the CD133 and CD44 molecules, may be a useful tool in preclinical research on therapeutic approaches, especially those targeting the CSCs of ovarian cancer.