Survival time of the two groups treated with IL-2 plus NAC and IL-2 only (study B). (Upper panel) The survival time of the 48 patients with at least two examinations. (Lower panel) The survival curves of the entire group of 70 recruited patients. (—) The IL-2 plus NAC–treated group. (---) The combined groups treated with either IL-2 alone or standard therapy. Among the patients that were indicated as alive was one patient with the last observation point at 319 days (IL-2 plus NAC group) and one patient with the last observation at 291 days (control group).