Low activity of manganese superoxide dismutase (MnSOD) in blood of lung cancer patients with smoking history: relationship to oxidative stress.

Lung cancer is the primary cause of cancer death in the world. Although it is well established that tobacco smoke causes lung cancer, not all smokers develop lung cancer. Manganese superoxide dismutase (MnSOD), a major determinant of antioxidants in matrix mitochondria, plays a pivotal role in eliminating anion superoxide free radical generated from the tobacco smoke.