Institution: | a Howard Hughes Medical Institute UCLA School of Medicine, 6780 MacDonald Building, Los Angeles, CA 90095-1662, USA b Department of Molecular, Cell and Developmental Biology, Immunology and Molecular Genetics, UCLA School of Medicine, 6780 MacDonald Building, Los Angeles, CA 90095-1662, USA c Department of Microbiology, Immunology and Molecular Genetics, UCLA School of Medicine, 6780 MacDonald Building, Los Angeles, CA 90095-1662, USA |