Department of Genome Sciences, University of Washington Seattle, WA, USA. noble@gs.washington.edu|Department of Genome Sciences, University of Washington Seattle, WA, USA. noble@gs.washington.edu|Department of Genome Sciences, University of Washington Seattle, WA, USA. noble@gs.washington.edu|Department of Genome Sciences, University of Washington Seattle, WA, USA. noble@gs.washington.edu|Department of Genome Sciences, University of Washington Seattle, WA, USA. noble@gs.washington.edu