BDNF and Friedreich ataxia: Studies have shown that MSCs release a plethora of potentially neuroprotective growth factors including brain-derived neurotrophic factor (BDNF), IGF-1, neurotrophin-3 [13, 15], stem cell factor (SCF) and granulocyte-colony stimulating factor (G-CSF) [40], some of which have already shown promising therapeutic potential for FA [31, 41, 42].