title: The molecular basis of positional signalling: introduction.
authors.affiliation: MRC Laboratory of Molecular Biology, Cambridge, UK.
authors.forename: R R
authors.initials: RR
authors.lastname: Kay
authors.forename: J C
authors.initials: JC
authors.lastname: Smith
mesh_terms: D000818:Animals; D002450:Cell Communication; D005314:Embryonic and Fetal Development / Q000502:physiology*; D015398:Signal Transduction