PTGS2 and cancer: It has been reported that cancer cells (HeLa, A549, and Myc-Cap/CR) treated with IL-17A induced more M2 polarization of RAW264.7 and THP-1 cells, which may be a result of the cyclooxygenase 2/prostaglandin E2 (COX-2/PGE2) pathway in the cancer cells (39).