“…The vast majority of ovarian tumors arise from the malignant transformation of ovarian surface epithelium, which displays a variety of Mušllerian-type cells, including serous, mucinous, endometrioid and clear cell, with a common pathway in embryologic development. Ovarian cancer develops in a multistep process that involves alterations of multiple pathways, including p16 INK4A , p21 Waf1/Cip1 , p27, cyclin D1, p53 and pRb (Kusume et al, 1999;Ferrandina et al, 2000;Prowse et al, 2003;Ozols et al, 2004;Kauff et al, 2005;Rosen et al, 2005). Our understanding of ovarian cancer is hampered by lack of human cell model system for studying early neoplastic changes (Vasey, 2003;Tammela and Odunsi, 2004).…”