HMOX1 and ganglioneuroma: The mRNA levels of genes involved in the antioxidant defense system (glutathione peroxidase 1 (Gpx1), heme oxygenase 1 (Hmox1), superoxide dismutase 1 (Sod1), thioredoxin reductase 1 (Txnrd1)) in GN muscle did not differ across the groups (Figure 7C).