PTGS2 and colonic neoplasm: This possibility is illustrated by a study in intestinal epithelial cell-6 cells (IE6) and Caco-2 colon cancer cells in which PAR2-driven prostaglandin E-2 (PGE2) production is a consequence of increased COX-2 expression, that results from a metalloproteinase-dependent transactivation of the EGFR.