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