While, the CBS inhibitor aminooxyacetic acid (AOAA) is also involved in regulating ROS levels and P53 activation 12, 16.Considering the antioxidant effect of H2S and the pivotal role of increased ROS in mediating the apoptosis induced by OXA, inhibition of H2S synthesis might sensitize colon cancer cells to OXA. The gene discussed is CBS; the disease is colonic neoplasm.