For instance, the MT-ND3 mutation disrupted the active/inactive transition of CI, and the MT-ND5 mutation inhibited proton translocation, both of which were found in patients with LS and LHON (Wang et al., 2009; Vodopivec et al., 2016; Lee et al., 2020). The gene discussed is MT-ND5; the disease is Leber hereditary optic neuropathy.