FAS and influenza: We defined memory subsets within influenza-specific A2/M158+CD8+ T cells across the human lifespan, namely Tnaïve (CD27+CD45RA+CD95-), Tscm (CD27+CD45RA+CD95+), Tcm (CD27+CD45RA-), Tem (CD27-CD45RA-), and Temra (CD27-CD45RA+) subsets, ex vivo (Fig. 1C and SI Appendix, Fig. S1B).