The prostaglandin receptor encoded using PTGER4 transmits upstream signals from the COX-2 enzyme and PGE2, thereby affecting tumorigenesis in the colon because PGE2 enhances various tumor-promoting factors, such as proliferation, expansion, angiogenesis, migration, and the invasion of colorectal carcinoma cells [23,24]. The gene discussed is PTGER4; the disease is colorectal carcinoma.