This study is an “investment” toward a molecular level of comprehension of the interaction between cats and viruses that infect them. Recently, “dendritic cells” (basic cell of the feline immune system) have been identified as the major orchestrator of immune responses. Dendritic cells are located throughout body surfaces, where they first detect invading microbes, and then activate the entire immune system. This proposal aims to discover many of the signals of the cat immune system by producing a library of genes expressed in dendritic cells. The genes of interest will then be printed on glass slides called microarray chips, which will be available to researchers for exact identification of the feline response to infection. Such chips will be a valuable tool for design of feline-specific drugs and treatments.