The most significant modulation occurred at 7 days post infection (Dpi) or 14 days of age (DoA), with upregulation of 6 genes in infected chicks, suggesting a peak in the type I interferon response (MX1), accompanied by a pro-inflammatory response and T cell differentiation (IL18, CEBPB, CD28, IL15). The gene discussed is MX1; the disease is infection.