In particular, regular aspirin use is much more effective at reducing risk in the group of patients whose colon tumors expressed high levels of PTGS2 (COX-2) [14] and improves overall survival after the diagnosis of CRC at stage I, II and III, again in individuals with tumors that overexpress PTGS2 (COX-2) [15]. Here, PTGS2 is linked to colonic neoplasm.