Background: Ovarian cancer (OC) is considered the most lethal cancer of the female reproductive system and ranked as the seventh most frequent cancer diagnosed worldwide and the eighth leading cause of cancer-related death among women worldwide. The most common type of Ovarian cancer is that originate from the ovarian surface epithelium "Epithelial ovarian cancer" (EOC) which accounts for over 90% of all ovarian malignancies and is the most lethal gynecologic malignancy. Sex determining region Y-box 2 (SRY)-box 2 (SOX2) is one of the main members of the Sox family which consists of at least 20 members that are divided into 8 groups (from A to H, based on their high mobility group (HMG) sequence identity in humans). SOX2 expression has been reported at both the RNA and protein levels for many tumors, data available from The Cancer Genome Atlas indicates that SOX2 mRNA is elevated in many cancers, relative to normal tissue. The level of SOX2 expression in a tumor represents a prognostic factor to determine the clinical outcome for a cancer patient. As SOX2 has a great role in cancer stemness so SOX2 expression in OC is an interesting issue for studying.