Another unique set of genes found upregulated in E-dominant male COPD are genes encoded in the mitochondrial genome and involved in oxidative phosphorylation, i.e. MT-CO1, MT-CO2, MT-CO3, MT-ND1, MT-ND2, MT-ND3, MT-ND5 and MT-ATP6. Here, MT-CO3 is linked to chronic obstructive pulmonary disease.