of maribavir for the wild type and mutant UL97 Proteins. The wild type and mutant UL97 proteins were subjected to protein kinase assays with varying concentrations of maribavir (0.01-1.0 μM). The autoradiographs were analysed using the BioRad Multianalyst software and UL97 phosphorylation plotted as a percentage of the total phosphorylation in the absence of maribavir. An exponential decay curve was fitted and the IC50 of maribavir was determined for each of the proteins. The alteration of x-axis scale of the M460I graph should be noted. The IC50 for each species is shown.