Funding for this research was provided by:
Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (147697)
Received: 24 January 2018
Accepted: 7 May 2018
First Online: 6 June 2018
Ethics approval and consent to participate
: Human embryonic lung tissue came from the specimen collection of the Unit of Anatomy, Section of Medicine, University of Fribourg, where donators had approved the use of tissue for teaching and research purposes. All experiments requiring mouse tissue (embryos) were performed with permission of the local animal care committee (Canton of Fribourg, Switzerland) and according to the present Swiss law and the European Communities Council Directive of 24 November 1986 (86/609/EEC).
: The authors declare that they have no competing interests.
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