PTGS1 and colorectal carcinoma: Decreased expression in CRC was also observed; it was significant and met the criteria for PTGS1 (other names include COX1, PGHS-1, and PTGHS), which encodes prostaglandin-endoperoxide synthase 1, which converts arachidonates to prostaglandines (key mediators in inflammation capable of playing a dual role, pro-inflammatory or anti-inflammatory, depending on context) [56].