Brown et al. demonstrated that TP induced expression of an oxidative stress marker HO-1 in human colon carcinoma cells (Colo320 cells) and human urinary bladder carcinoma cells (RT112 cells), and discussed that the DR generated by TP during thymidine catabolism may contribute to ROS production by finally being converted to enediol via schiff base reactions9. The gene discussed is HMOX1; the disease is colon carcinoma.