Ari Helenius is intrigued by the deceptive simplicity of a virus: "You can understand it on a molecular level, know every component of it, but its interaction with host cells turns on extremely complicated biology." This veteran virologist at ETH Zurich has spent a career tracking the complex interactions of pathogen and host (see "Foundations: Viral Cell Entry"). In "The Orange and the Circus Tent", Helenius charts his life-long love affair with virology. "The construction of the human system can hardly be understood unless considered from the point of view that it's a target."













