Data presented show that intradermal (i.d.)infection with VACV lacking N1 (vΔN1) or bearing the I6E mutation (vN1.I6E) caused increased activation of CD8+ T cells compared with wild-type (WT) virus (vN1.WT), illustrating the importance of NF-κB signalling for induction of T-cell responses. The gene discussed is CD8A; the disease is infection.