Sonic hedgehog

This article is about a gene and protein. For the character, see Sonic the Hedgehog. For eponymous media see Sonic the Hedgehog (disambiguation).

Sonic hedgehog homolog (SHH), named after Sonic the Hedgehog, is one of three proteins in the "hedgehog" family, the others being desert hedgehog (DHH) and Indian hedgehog (IHH). The protein is known to be involved in embryonic development of digits on limbs and organisation of the brain. The sonic hedgehog gene (shh), required for the transcription of the protein, is found in the mammalian genome.