The Hedgehog proteins are a family of secreted ligands that include sonic hedgehog, Indian hedgehog and desert hedgehog in humans. Binding of Hedgehog ligands to their receptors, Patched 1 and 2, prevents inhibition of a 7 transmembrane receptor called Smoothened. This leads to activation of GLI family of transcription factors (GLI1-3). Signaling through the Hedgehog pathway is essential for development of many tissues and organs. This pathway is highly conserved among metazoans. Aberrant activation of this pathway has been associated with a number of human malignancies including carcinoma of lung, esophagus, pancreas and prostate.

This diagram is based on a schematic created by the NetPath human pathway annotation project and has been modified for use on this site. The NetPath project is a joint effort between the Pandey lab at Johns Hopkins University and the Institute of Bioinformatics. The diagram was built using the GenMapp annotator and pathway profiler.