Program in Computational Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA. mtmorgan@fhcrc.org|Program in Computational Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA. mtmorgan@fhcrc.org|Program in Computational Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA. mtmorgan@fhcrc.org|Program in Computational Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA. mtmorgan@fhcrc.org|Program in Computational Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA. mtmorgan@fhcrc.org|Program in Computational Biology, Fred Hutchinson Cancer Research Center, Seattle, WA, USA. mtmorgan@fhcrc.org