PTGS2 and colorectal carcinoma: Regarding CRC, it was reported that administration of celecoxib, a selective COX-2 inhibitor, significantly decreased the frequency of Gr1+CD11b+ immature myeloid-suppressor cells (I-MSCs) during chemoprevention of 1,2-dimethylhydrazine diHCl-(1,2-DMH) in CRC mice [80].