Our study shows that, compared with TB patients without DILI: (1) those with DILI had more mtDNA variants in ND5 gene; and (2) Patients with isoniazid-induced DILI not only had more mtDNA variants in ND1 and ND5 genes but also had more nonsynonymous substitutions, which lead to amino acid changes, in ND5 gene, and a higher average ratio of nonsynonymous to all substitutions across the entire mitochondrial genome. The gene discussed is MT-ND1; the disease is tuberculosis.