We wanted to further explore the potential of both 2D gel electrophoresis and quantitative MS/SILAC to examine the effects of adenoviral infection on the host cell. As stated, we have previously shown that nucleolar antigens UBF and B23 are visibly depleted from the nucleolus during adenovirus infection and play functional roles in viral DNA replication (11) (12) (13) . Thus, we would expect a proteomics approach to confirm these well established changes in nucleolar composition that are of functional relevance to the infection. This study not only identified proteins known to be affected by adenovirus infection, but it also identified a number of novel alterations to the nucleolar proteome that were subsequently examined by confocal microscopy for independent verification.