SUMMARY - HUMANIZED MOUSE CORE (CORE A) The huNSG mouse model nicely recapitulates aspects of human biology that are not supported in other systems. This humanized mouse model also offers the only small animal model capable of supporting HCMV infection, latency, and reactivation. This PPG requires our highly standardized huNSG model in order to effectively characterize unique conditions and quantitatively differentiate viral growth and dissemination of different viral mutants and treatments. Core A will provide the infrastructure and knowledge required for completion of the proposed research projects involving huNSG mice and standardize analysis between all projects to allow for direct comparisons. By working directly with the Project leaders, Core A will aid in designing and execution of the proposed experiments.