Altered T-cell differentiation in the presence of IFN-λ1. Purified naive (A) or memory (B) CD4⁺ T cells were stimulated under neutral (only anti-CD2/3/28 beads) or Th2 conditions (anti-CD2/3/28 beads + 10 ng/mL IL-4). Each cell type was cultured in the presence or absence of IFN-λ1 for 3 days, harvested, and stained with PE-labeled anti-CCR7 and PECy5.5-labeled anti-CD62. Percentages shown denote expression of CD62L and CCR7 as analyzed by flow cytometry. One representative experiment of 4 is shown.