In lung and spleen tissues of 3-week-old Pekin ducks taken at 24 h of infection with H5N1-tyTR05 virus, despite the detection of virus matrix gene expression (Figure 5H), LITAF (Figure 5E) expression was significantly down-regulated (p < 0.05); IL-6 (Figure 5F) and IL-8 (Figure 5G) expression was not significantly affected (p > 0.05). This evidence concerns the gene CXCL8 and infection.