Other genes such as CYP3A4, CYP2C9, ADH4, ADH1A, and CYP1A2 enriched in the cytochrome P450 pathway are observed as metabolically active procarcinogens to genotoxic intermediates, and an association has been found between CYP enzyme activity and the risk to develop several forms of cancer. This evidence concerns the gene CYP2C9 and cancer.