Therefore, to assess the kinetics of IL-6Rα and IL-7R expression in vivo, we infected mice with influenza (A/PR8/34; ‘PR8') and monitored antigen-specific (nucleoprotein, ‘NP'-specific) CD4+ T cells at multiple time points post infection (days post infection, d.p.i.). The gene discussed is IL7R; the disease is influenza.