Authors suggest a clear advantage of using the NDI1 gene over allotopic expression of mammalian mitochondrial complex I subunit genes as a therapy for LHON and that a single gene may provide benefit to all LHON patients with a complex I deficiency irrespective of which complex I subunit gene is causative of this debilitating retinopathy. The gene discussed is AVPR2; the disease is Leber hereditary optic neuropathy.