The potential explanations for reduced enzyme activity in the oral cancer group include elevated OS due to an accumulation of ROS, insufficient production of antioxidant enzymes and excessive utilization or degradation of SOD by reactive oxygen metabolites, intensive utilization of SOD to counteract superoxide anion (free radicals/ROS), and limited antioxidant capacity to neutralize ROS in a cancerous environment. Here, SOD1 is linked to lip and oral cavity carcinoma.