While both naive and memory T cells can receive TCR signals via self-peptide/MHC interactions during steady-state37,42, the herein described γc cytokine receptor alterations in both antigen-specific and bystander T cells are likely caused by a protracted increase in concentrations of IL-7 and IL-15 due to lymphopenia following acute viral infection. The gene discussed is IL7; the disease is lymphopenia.