A subsequent electroporation with the wild-type ND4 sequence prevented RGC loss and the impairment of visual function [125] In a subsequent study, Guy and colleagues demonstrated that an MTS-targeted AAV carrying the mitochondrial gene encoding the human ND4 prevented the optic atrophy induced by the mutant R340H ND4 [126]. Here, MT-ND4 is linked to Leber hereditary optic neuropathy.