Previous clinical trials of peptide immunotherapy found that 10 μg C19-A3 proinsulin peptide s.c. every 2 weeks was well tolerated in patients with recent-onset T1D (31), while 60–150 μg weekly s.c. administration of celiac disease–relevant peptides induced dose-dependent gastrointestinal symptoms associated with T cell IL-2 production (32–34). The gene discussed is IL2; the disease is type 1 diabetes mellitus.