@article {4960,
	title = {Sequential phosphorylation of smoothened transduces graded hedgehog signaling},
	year = {2011},
	doi = {10.1126/scisignal.2001747},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/21730325},
	author = {Ying Su and Jason K. Ospina and Junzheng Zhang and Andrew P. Michelson and Adam M. Schoen and Alan Jian Zhu}
}
