1 Sanford I. Weill Department of Medicine, Sandra and Edward Meyer Cancer Center, Weill Cornell Medicine, New York, NY, USA. efa2001@med.cornell.edu.
2 Donald E. and Delia B. Baxter Foundation Professor for Stem Cell Biology, Stanford University School of Medicine, Stanford, CA, USA. hblau@stanford.edu.
3 Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden. kenneth.chien@ki.se.
4 MRC Laboratory of Molecular Biology, Cambridge, UK. madeline.lancaster@mrc-lmb.cam.ac.uk.
5 Department of Cell Biology and Duke Regeneration Center, Duke University School of Medicine, Durham, NC, USA. pt93@duke.edu.
6 IRCAN Institute for Research on Cancer and Aging, INSERM Unité 1081, CNRS UMR 7284, Université Côte d'Azur, Nice, France. etrompouki@unice.fr.
7 Directors' Research Unit, European Molecular Biology Laboratory, Heidelberg, Germany. fiona.watt@embo.org.
8 State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Science, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China. yzeng@sibcb.ac.cn.
9 School of Life Science, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, China. yzeng@sibcb.ac.cn.
10 Mammalian Embryo and Stem Cell Group, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK. magdaz@caltech.edu.
11 Stem Cells Self-Organization Group, Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA. magdaz@caltech.edu.