RESEARCH ARTICLE MicroRNA-21 is a candida

Full list of author information is available at the end of the articleBackground Epithelial ovarian cancer (EOC), a heterogeneous group of neoplastic diseases that arise from the epithelial cells of fallopian tubes, ovarian fimbria, ovarian surface epi-thelium, inclusion cysts, peritoneal mesothelium, or endometriosis, is the most lethal gynecologic malignancy in western countries and in Japan [1]. EOC can be classi-fied into four major histological types: serous, mucinous, endometrioid adenocarcinoma, and clear cell carcinoma (CCC). CCC has unique clinical characteristics that differ from other histological types of EOC. CCC accounts for 5–25 % of all EOC, depending on the population. The prevalence of CCC among EOCs in North America and Europe is 1–12%, while that in Japan is approximately 20 % [2]. CCC is frequently associated with coexistent * Correspondence