As one possible means to explain the poor efficacy of Treg induction by natural insulin B-chain epitopes in murine T1D, it has been indicated that the insulin-B-chain peptide is presented by I-Ag7 in a low-affinity binding register, which results in weak-agonistic activity of the peptide presented by the major histocompatibility complex (MHC)II (refs 7, 28). The gene discussed is INS; the disease is type 1 diabetes mellitus.