The invention also provides a method for modulating {HEAD ~ proliferation} or differentiation of {TAIL ~ neuronal cells} comprising contacting the cells with a hedgehog polypeptide 
of
The invention also provides a method for modulating { HEAD ~ proliferation } or differentiation of { TAIL ~ neuronal cells } comprising contacting the cells with a hedgehog polypeptide
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH