GPX1 and Friedreich ataxia: Using immunoblotting techniques and image analysis using ImageJ software, it was calculated that FXN-transfection in fibroblasts-derived from FRDA patients led to a 4-fold increase in catalase expression (p<0.05), no significant increase in glutathione peroxidase 1 expression was evident (p>0.05) (Figure 5C & Figure 5D).