A 1.5- to 2-fold increase in frataxin protein expression was observed in lymphoblasts and fibroblasts derived from individuals with FRDA, and a 200 mg/kg subcutaneous RSV resulted in a 1.5-fold increase in human frataxin protein in the brain of humanized FRDA (YG8R) mice [79]. Here, FXN is linked to Friedreich ataxia.