Transcriptional profiling arrays have been developed to examine genome-wide expression of EBV and KSHV [18, 19] . However, humoral immune responses to EBV and KSHV proteins have predominantly been measured using virus-infected cell lines or enzyme-linked immunosorbent assays that incorporate just a few selected viral proteins [2] [3] [4] [20] [21] [22] . Although these assays have proven valuable for diagnostic and epidemiological studies, they do not provide a complete picture of the full repertoire of antibody responses generated by EBV and KSHV infection. High-throughput technologies allow cloning and expression of entire pathogen proteomes [23, 24] . We used this technology to generate proteomic microarrays for EBV and KSHV. These arrays allowed us to compare the global humoral immune responses to EBV vs KSHV in the same patient samples and within the same assay.