Overexpression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) are correlated to colorectal carcinogenesis, and inhibition of their activities leads to cancer prevention (Sheehan et al., 1999; Rao et al., 1999; de Oliveira et al., 2017). This evidence concerns the gene PTGS2 and cancer.