Because ATL cells typically have a Treg-like suppressor phenotype (45, 46) and since the absence of BLIMP1 resulted in enhanced IL-2 signaling in cTreg cells during influenza infection, we next investigated the role of BLIMP1 in IL-2 signaling in ex vivo–isolated Treg cells. The gene discussed is PRDM1; the disease is influenza.