Although heteroplasmies at mutational sites in ND2 and ND4 are highly specific for BA, such mutations did not seem to be accumulated with aging due to the fact that one BA group (i.e., 9, 12, 14, and 17) with more severe hepatic dysfunction is relatively younger than the other BA group (i.e., 8, 13, 16, and 19) (Table 2). Here, MT-ND2 is linked to breast angiosarcoma.