The insulin superfamily consists of peptides such as vertebrate insulins, mammalian relaxin and insulin-like growth factors, and invertebrate insulin-like peptides (ILP). They are synthesized as pre-propeptides and processed to yield two peptides, A and B, linked by disulfide bonds. ILPs have been identified throughout invertebrate species. In D.mel, ILPs may function as peptide hormones and/or neuropeptides. They have been linked to the regulation of growth and development. (Adapted from FBrf0189697 and FBrf0152330).