BDNF and Friedreich ataxia: Finally, Quesada et al. [47] described an overexpression of iron–sulfur cluster genes and other oxidative stress-related genes, active-caspase 3, and other apoptosis-related genes, as well as the upregulation of brain-derived neurotrophic factor (BDNF), neuregulin 1, and miR-132 in periodontal ligament cells from patients with FRDA compared to HC.