Plays a role in regulating body size by increasing cell size and cell number of individual organs. Probably mediates its growth effects by acting as a ligand for the insulin receptor and transducing a signal via the Chico/PI3K/Akt(PKB) pathway. Heterodimer of a B chain and an A chain linked by two disulfide bonds. Broadly expressed at a low level in the embryonic mesoderm, beginning at stage 12. Expressed at a high level in the embryonic anterior midgut, with expression diminishing at late stage 16. Expressed at a low level in larval imaginal disks. Expressed at a high level in larval salivary glands and in seven cells of each larval brain hemisphere that may correspond to neurosecretory cells. Expressed in the embryo and larva. Of the insulin-like peptides, Ilp2 is the closest homolog of human insulin. Belongs to the insulin family.