PTGS2 and ovarian carcinoma: However, in ovarian cancer, SC-560 (a COX-1 inhibitor) can suppress the production of PGE2 whereas while NS-398 and rofecoxib (COX-2 inhibitors) cannot, which suggests the COX-1 is the primary enzyme for producing PGE2 instead of COX-2 in ovarian cancer cells (Kino et al., 2005).