Two patients had received immunotherapy (anti-GD2 antibodies for neuroblastoma and anti-thymocyte globulin with cyclosporin for aplastic anemia), and two patients with non-malignant hematological disorders (aplastic anemia and ADA2 deficiency) had not received any immunosuppressive therapy whatsoever. This evidence concerns the gene ADA2 and hyperinsulinemic hypoglycemia, familial, 4.