In mouse viral lung disease Ccl5 mRNA in the lung peaks less than a day after primary viral infection with Ccl5 production by resident epithelial cells and lung macrophages during the innate immune response, and then in a second wave at 7 dpi, primarily with Ccl5 production by infiltrating CD4+ and CD8+ T cells (54). The gene discussed is CD4; the disease is viral infectious disease.