García-de-la-Asunción et al. investigated whether 80% fraction of inspired oxygen (FiO2) inhalation throughout surgery reduces xanthine oxidase (XO) action in colonic mucosa as a likely mechanism of decreasing oxidative stress during colon surgery of colon cancer patients (García-de-la-Asunción et al., 2011). This evidence concerns the gene XDH and malignant colon neoplasm.