FXN and diabetes mellitus: Frataxin (FXN), a ubiquitous and highly conserved mitochondrial protein, is associated with Friedreich’s ataxia (FRDA), a cardio- and neurodegenerative disease characterized by progressive gait and limb ataxia, dysarthria, loss of proprioception and coordination, diabetes mellitus and hypertrophic cardiomyopathy, which represents the primary cause of death [1,2,3,4].