Sonic Hedgehog （SHH） is a secreted factor which expressed in embryonic tissues that are critical for the patterning of the developing central nervous system, somite, and limb. SHH binds to the patched receptor, which functions in association with smoothened, to activate the transcription of target genes. In the absence of SHH, patched receptor represses the constitutive signaling activity of smoothened. SHH also regulates another factor, the gli oncogene. It regulates neural and hematopoietic stem cell fate and is important for thymocyte differentiation and proliferation as well as T cell determination. SHH-N is highly conserved, sharing >98% aa identity between mouse, human, rat, canine, porcine, and chicken Shh-N. Shh-N can be palmitoylated at itsThe Shh-N protein is highly conserved, sharing >98% aa identity between mouse, human, rat, canine, porcine, and chicken Shh-N. Shh-N can be palmitoylated at its N-terminal cysteine and modified by cholesterol addition at its C-terminus. These modifications contribute to the membrane tethering of the Shh protein as well as its assembly into various sized multimers.