IFNA1 and melanoma: Subgroup analysis showed improved impact of PEG-IFN upon RFS in stage III-N1 melanoma patients and in this subset an impact was also observed upon DMFS [p = 0.016, HR = 0.73 (95% CI = 0.53–1.02) and p = 0.03, HR = 0.75 (95% CI = 0.52–1.07) respectively], although there is no evidence of an impact upon OS [p = 0.43, HR = 0.88 (95% CI = 0.58–1.33)].