SOD1 and idiopathic pulmonary fibrosis: Between June and September 2007, a total of 55 patients (diagnosis of IPF, n = 47; srf-NSIP, n = 8) were randomly allocated to receive either a placebo (n = 18), 40 mg of PC-SOD (n = 18), or 80 mg of PC-SOD (n = 19).