1. Imaging and Bioinformatics Group, Leiden Institute of Advanced Computer Science (LIACS), Leiden University , Leiden 2333 CA , The Netherlands
2. Division of Drug Discovery and Safety, Leiden Academic Centre for Drug Research, Leiden University , Leiden 2333 CC , The Netherlands
3. Applied Stem Cell Technologies, TechMed Centre, University of Twente , Enschede 7522 NB , The Netherlands
4. Department of Anatomy and Embryology, Leiden University Medical Centre , Leiden 2300 RC , The Netherlands