MT-ND5 and breast cancer: Table 2 shows the distribution of somatic and germline mutations among OXPHOS components (complexes I, III, IV and V) encoded by mtDNA. There are no major variations in mutation distribution between the germline and somatic mutations (Fisher P = 0.159). The Complex I genes, however have the largest number of somatic mutations (36.9%) and germline mutations (25.5%). Interestingly, ND5 gene of Complex I harboured the largest number of somatic (37.5%) and germline mutations (26.0%) (Fig 4), consistent with a previous breast cancer study [34].