The peak expression of IL-6 and TNFα upon influenza infection was reached faster in C57BL/6 wild type mice at day 1 post infection (Figure 2G) as compared to day 3 in BALB/c mice (Figure 3E), and thus coincided with the earlier response in pulmonary resistance observed in the C57BL/6 strain (Figure 3C). This evidence concerns the gene IL6 and infection.