Probably required to stimulate the proliferation, polarization and motility of imaginal disk cells. May act by stabilizing the binding of insulin-like peptides to its receptor through a simultaneous interaction with both molecules to form a multiprotein signaling complex (By similarity). Secreted in hemolymph. It is probably transported to target tissues via hemolymph. Glycosylated. Lacks the typical Glu active site in position 161 that is replaced by a Gln residue, preventing the hydrolase activity. Its precise function remains unclear. Belongs to the glycosyl hydrolase 18 family. IDGF subfamily.