We have previously demonstrated that certain ROS-generating mtDNA mutations in the ND6 gene, G13997A and 13885insC, enhance metastasis in low-metastatic Lewis lung carcinoma cells and fibrosarcoma cells, respectively6,7, providing the first report of the involvement of pathogenic ND gene mutations in metastasis. The gene discussed is MT-ND6; the disease is Carcinoma, Lewis Lung.