Department of Computer Sciences, University of Wisconsin, Madison, WI, USA.|Wisconsin Institute for Discovery, University of Wisconsin, Madison, WI, USA.|Department of Oncology, University of Wisconsin, Madison, WI, USA.|Institute for Molecular Virology, University of Wisconsin, Madison, WI, USA.|Microsoft Research, Redmond, WA, USA.|Department of Oncology, University of Wisconsin, Madison, WI, USA.|Institute for Molecular Virology, University of Wisconsin, Madison, WI, USA.|Department of Computer Sciences, University of Wisconsin, Madison, WI, USA.