T-cell outcomes in response to chronic or recurrent infection include the adoption of dysfunctional phenotypes of senescence, exhaustion and cytotoxicity, which have all been reported to be marked by CD57 expression and/or CD45RA reversion of effector memory cells (TEMRA), but the ontogeny, function and significance of these CD4+ T-cell outcomes remain to be clearly resolved [6, 7]. Here, CD4 is linked to infection.