Highly conserved proteins, members of the Hedgehog family are widely represented throughout the animal kingdom. The three known mammalian Hedgehog proteins; Sonic (SHH), Desert (DHH) and Indian (IHH) hedgehog share a high degree of sequence and structural identity. SHH is specifically known to be expressed in fetal intestine, liver, lung and kidney. Recombinant Human SHH represents the N-product (N-terminal domain with Cys24 substituted by an Ile-Val-Ile sequence) which retains all the known signalling capabilities.