We infected myeloid cell populations in vitro using a multiplicity of infection of 1 that leads to an infection efficiency of less than 60% (see Fig. 3A for example), enabling us to compare surface CD200 protein levels on uninfected and infected cells from the same well of a tissue culture plate, as identified by flow cytometric detection of the intracellular MCMV m06 protein. The gene discussed is CD200; the disease is infection.