Our initial foray into the world of genomics began with cDNA microarrays that were spotted in-house using a commercially available collection of cDNA clones. Getting this new technology up and running required months of work. But after seemingly endless frustration, Gary Geiss was finally able to use these arrays, representing all of 1,500 human genes, to evaluate the changes in cellular gene expression that occurred in a CD4+ T-cell line infected with human immunodeficiency virus type 1 (HIV-1) [2] . This was a straightforward study in which we analyzed two time points after infection, and we were thrilled to observe the temporal regulation of genes involved in T-cell signaling, subcellular trafficking, and transcriptional regulation. Despite how simplistic this study now appears, it was the first ever to apply genomics to AIDS research and it was the cover article when published in Virology. With the technology now in place, we were eager to apply it to a broad range of experimental systems. The possibilities seemed endless (as indeed they are), and we rapidly began "doing arrays" on cells infected with a variety of different viruses or exposed to double-stranded RNA (dsRNA), interferon, or other treatments ( Figure 1 ).