Western blot analysis showed that compared to control HMEC cells, expression of the G-protein coupled EP receptors, EP1-4, COX-2 and microsomal prostaglandin E synthase-1 (mPGES-1) were significantly upregulated in the breast cancer cells SUM149PT and SUM1315MO2 (Figure 4A). Here, PTGES is linked to breast carcinoma.