Related genes constitute a multi-gene family with numerous roles in vertebrate development.
In addition to these functions, other studies suggest potential roles of vertebrate hh proteins in the development of skin, teeth, gut, bladder, bone and testis. The aberrant activation of the hh signaling pathway also has been implicated as the cause of basal cell carcinoma, the most common form of human cancer. The hh family of signaling proteins thus have emerged as important regulators of animal cell proliferation and differentiation. Our recent work indicates an important role for cholesterol in hh protein synthesis and function. Beyond simple peptide bond cleavage, however, the autoprocessing reaction involves ligation of a cholesterol moiety to the amino-terminal domain at the site of cleavage.