Sonic hedgehog

The sonic hedgehog protein (SHH) is coded by the "SHH" gene. The protein is named after the character "Sonic the Hedgehog".
This key signalling molecule "regulates embryonic development in all animals". SHH controls organogenesis and the organization of the central nervous system, limbs, digits and many other parts of the body. Sonic hedgehog is a morphogen that patterns the developing embryo using a concentration gradient.
Abnormal activation of SHH signalling in adult tissues causes various types of cancers.