Most human colorectal cancers exhibit marked elevation of cyclooxygenase-2 (COX-2) expression.4,5 Moreover, the COX-2 and prostaglandin E2 (PGE2) receptor subtypes are reportedly involved in intestinal carcinogenesis and activation of multiple signalling pathways.6–8 PGE2 receptor 2 (PTGER2) and PGE2 receptor 4 (PTGER4) receptors activate PGE2, triggering a series of events,9 with several studies indicating that PGE2 mediates the effects of chronic inflammation on colorectal cancer stem cell (CSC) expansion and chemoresistance.10,11. The gene discussed is PTGS2; the disease is colorectal cancer.