This finding ruled out that CyCMV-specific CD8+ T cell immunity protected against infection with RhCMV, and instead indicated that UL36, UL128 or UL130, genes missing in RhCMV 68–1, but repaired in RhCMV 68–1.2, are required for cross-species infection of MCM with RhCMV (Fig 1). Here, CD8A is linked to infection.