MT-ND4 and Leber hereditary optic neuropathy: In fact, Ndi1 expression improved OXPHOS capacity and restored NADH oxidase activity in Mdivi-1 expressing COS-7 cells [38], complex I deficient human 143B osteosarcoma cells [32,39], and a 143B cell model of Leber’s hereditary optic neuropathy (LHON) bearing the G11778A mutation in the ND4 subunit of complex I [30].