TFAM and chronic obstructive pulmonary disease: We demonstrated that 1) the expression of mtTFA mRNA and protein was lower in the lung tissue of COPD patients with squamous lung cancer as compared to squamous lung cancer patients without COPD; 2) the expression of mTFA was positively correlated with vascular endothelial cell apoptotic index; 3) but was negatively correlated with cigarette smoking index.