@article {cite-key,
	title = {Developmental biology. Making head or tail of Dickkopf.},
	journal = {Nature},
	volume = {411},
	number = {6835},
	year = {2001},
	month = {May},
	pages = {255{\textendash}256},
	issn = {0028-0836 (Print); 0028-0836 (Linking)},
	doi = {10.1038/35077199},
	author = {Nusse, R}
}
