Although it is known that CYP2C9 y CYP2C8 have common substrates including NSAIDs (Garcia-Martin et al., 2004; Martinez et al., 2005; Totah and Rettie, 2005), a putative association between CYP2C8 polymorphisms and colorectal cancer risk has not been analyzed in detail. Here, CYP2C9 is linked to colorectal cancer.