In HT-29 colon cancer cells, βPix deficiency greatly reduced expression of PTGS2 mRNA (p < 0.001; Fig. 5h), whose gene product, prostaglandin-endoperoxide synthase-2 [PTGS2; cyclooxygenase-2 (COX2)], catalyzes arachidonic acid metabolism. This evidence concerns the gene PTGS2 and malignant colon neoplasm.