The levels of IL-6, which stimulates an immune response, and CCL5, which plays an active role in recruiting leukocytes into the site of inflammation increased by about 100-fold (IL-6) or >tenfold (CCL5) after rPR/8 and rPR/8 × MINS virus infection, whereas the rPR/8 × KYGNS infection group showed no significant increase in the levels of these two pro-inflammatory cytokines (Figures 4A and B). This evidence concerns the gene CCL5 and viral infectious disease.