MT-ND4 and Leber hereditary optic neuropathy: Preliminary results provided by several clinical trials have shown that gene therapies such as rAAV2-ND4 and scAAV2- (Y444, 500, 730F) P1ND4v2 were well tolerated and improved visual outcomes of G11778A LHON patients [50, 64, 66, 77–79].