Indeed, 7 days following infection with vaccinia virus, greater than 90% of the virus‐specific cells identified with DimerX staining expressed a GzmBhiCD62Lo phenotype.45 Similarly, integrin CD11a expression and CD8α downregulation were identified as stable markers for tracking TCR‐transgenic cells specific for LCMV.46 However, CD11a expression is not always distinct and the extent of CD8α downregulation is proportional to the strength of antigen recognition, and varies with the nature of stimulation. This evidence concerns the gene CD8A and infection.