NFE2L2 and Friedreich ataxia: Paramount to the effects of Nrf2 on mitochondrial function, a pivotal clinical trial of omaveloxolone in patients with Friedreich's ataxia was recently completed.[8, 9] Friedreich's ataxia is a disease caused by a deficiency in frataxin, a protein involved in the assembly of iron–sulfur clusters, which leads to increased free radicals, oxidative stress, and disruption of mitochondrial homeostasis primarily in the cerebellum, liver, and heart.