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