Sonic Hedgehog Homolog

The best studied of the 3 protein ligands—the other 2 are desert hedgehog (DHH) and Indian hedgehog (IHH)—in the hedgehog family of mammalian signaling pathway ligands. SHH is a morphogen which plays a key role in regulating vertebrate organogenesis—e.g., growth of digits on limbs—and organisation of the brain, diffusing to form a concentration gradient that has different effects on the cells of the developing embryo depending on its concentration. It remains important in adults, controlling cell division of stem cells and has been implicated in development of some cancers