1 Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, Texas, USA. Electronic address: donald.glass@utsouthwestern.edu.
2 Department of Developmental Biology, Washington University School of Medicine in St. Louis, St. Louis, Missouri, USA. Electronic address: g.riveragonzalez@email.wustl.edu.
3 Department of Molecular, Cellular and Developmental Biology, Yale School of Medicine, New Haven, Connecticut, USA. Electronic address: valerie.horsley@yale.edu.
4 Department of Dermatology, Stanford University Medical Center, Stanford, California, USA. Electronic address: eleni.linos@stanford.edu.