SLCO2A1 and colorectal cancer: In another scenario, cyclooxygenase-2 (COX-2) overexpression along with downregulation of tumor suppressor 15-prostaglandin dehydrogenase (15-PGDH) and prostaglandin transporter (PGT) in colorectal cancer increases levels of its pro-tumorigenic product prostaglandin E2 (PGE2).