1. Department of Microbiology and Environmental Toxicology, University of California Santa Cruz, Santa Cruz, California, USA
2. Department of Pathology, University of South Alabama College of Medicine, Mobile, Alabama, USA
3. Department of Molecular, Cellular, and Developmental Biology, University of California Santa Cruz, Santa Cruz, California, USA
4. Institute for the Biology of Stem Cells, University of California-Santa Cruz, Santa Cruz, California, USA
5. Institute of Experimental Immunology, University of Zürich, Zürich, Switzerland