PTGS2 and cervical squamous intraepithelial neoplasia: In light of the paucity of research on the expression of COX-2 in cervical cancer, we have examined the expression pattern of COX-2 in Cervical Intraepithelial Neoplasia (CIN), various forms of cervical cancer and its relationship to tumor differentiation, parametrial and lymphovascular invasion in the present study [6].