ALCAR has the advantageous property of crossing the blood–brain barrier, and this molecule promotes OXPHOS by upregulating the transcript levels of ‘master' genes involved in mitochondrial biogenesis, namely PGC-1α, PGC-1β, and TFAM.81, 82 A study is currently nearing completion looking at the effect of ALCAR on neuronal conduction along the visual pathways in patients with chronic LHON and disease duration of more than 2 years (http://apps.who.int/trialsearch/trial.aspx?trialid=EUCTR2009-016982-26-IT, accessed on 8 December 2013). This evidence concerns the gene TFAM and Leber hereditary optic neuropathy.