PTGS2 and esophageal squamous cell carcinoma: In this study, we investigated the effect of lipophilic simvastatin and hydrophilic pravastatin on the proliferation of esophageal cancer adenocarcinoma OE-19 cells and esophageal squamous cell carcinoma Eca-109 cells, and analyzed their effect on the expression of COX-2 and its downstream product PGE2.