Mark Twain once remarked that the reports of his death were greatly exaggerated. So too, the death of virology. In certain quarters, it is now fashionable to declare the passing of virology. “Viruses are retro,” a faculty colleague once told me, deadly serious. We have heard this before. In 1967, the U.S. Surgeon General allegedly proclaimed, “The time has come to close the book on infectious disease. We have basically wiped out infection in the United States” (1). This was before the arrival of AIDS and severe acute respiratory syndrome (SARS) and the discovery of hepatitis C virus, before the fear of an avian flu pandemic and bioterrorism. Virology was once held in high esteem. In the first half of the 20th century, plant viruses held center stage. Studies of mosaic disease of tobacco revealed the existence of a new class of infectious agents smaller than bacteria, and tobacco mosaic virus taught us that viruses could be crystallized, disassembled, and reassembled into an infectious form: “life” could be studied with chemical approaches (2, 3). In the 1950s and 1960s, viruses that infect bacteria played a central role in the biological sciences. They formed the basis of the Hershey-Chase experiment, the first widely accepted evidence that DNA is the genetic material (4). Bacteriophage also led to the discovery of mRNA and the triplet nature of the genetic code and played a leading role in the birth of molecular biology (5). The 1970s and 1980s were a golden age for animal virology. The small genomes of many animal viruses and the ease of introducing them into cells made them the model organisms of choice to study eukaryotic cells. mRNA splicing, transcriptional enhancers, oncogenes, tumor suppressor proteins, antiapoptotic proteins, cellular trafficking signals and pathways, major histocompatibility complex (MHC) restriction, and much fundamental …