First, compared with the age- and sex-matched control group, patients with IPF had (A) similar co-morbidities, higher mortality, and more mitochondrial COX3 gene NS variants (substitution/deletion/insertion), which lead to amino acid substitution, truncation, or a completely different protein of the COX3 subunit of cytochrome c oxidase; (B) more mitochondrial tRNA variants that were located in the AC arm, AC loop, variable loop, T-arm, and T loop than the control group. This evidence concerns the gene MT-CO3 and idiopathic pulmonary fibrosis.