The mouse model with a selective Tfam knockout in fast-twitch skeletal muscle fibers (Tfam KO) has been shown to mimic pathological features typically reported in patients with mitochondrial myopathies, including ragged-red fibers with abnormally positioned and enlarged mitochondria, atrophic fibers, COX-deficient fibers and a reduction of respiratory chain enzyme activities (Aydin et al., 2009; Wredenberg et al., 2002). This evidence concerns the gene TFAM and Mitochondrial myopathy.