The number of viral genomes detected in the spleens of infected mice were equivalent for each MCMV strain irrespective of infection protocol, with no enhancement of C4A or C4B viral DNA levels in multi-strain (Figure 1C) compared to single strain (Figure 1B) infected mice, and no enhancement or reduction in the DNA load of C4C or C4D MCMV strains in multi- compared to single- strain infected mice. The gene discussed is C4B; the disease is infection.