The transient expression of CD68 in macrophages, MHC Class II in endothelial cells and GFAP in astrocytes at 4 days p.i. demonstrates that cellular pro-inflammatory responses are triggered during acute infection and, like the cytokine and chemokine responses, rapidly return at 7–10 days p.i. to levels observed in uninfected macaques. The gene discussed is CD68; the disease is infection.