PTGS2 and cancer: Prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclooxygenase) (PTGS2), whose upregulation is associated with carcinogenesis and cancer progression [53], was not expressed in any of the three kidney regions (NOR, PTA, PTB) but was turned on in CWM (AVE(CWM) = 0.49).