For histological sub-type, COX-2 over-expression in HGSC, LGSC, mucinous carcinoma, clear cell carcinoma and carcinosarcoma were 69.2% (18 of 26), 22.2% (2 of 9), 33.3% (3 of 9), 50% (1 of 2) and 100% (1), respectively. Here, PTGS2 is linked to clear cell adenocarcinoma.