Within CD4+ naïve T-cells, RTEs can be identified by their higher expression of the platelet endothelial cell adhesion molecule-1 (PCAM-1 or CD31) [40] . While the number of RTEs was similar in HCV-infected patients at study entry and healthy individuals ( These data demonstrate that, as early as one month following treatment initiation, IFNa induces stronger alterations of naïve Tcell subsets, and more specifically in the RTE compartment than in any other T-cell subset, suggesting a specific effect on thymopoiesis. We thus analyzed the evolution of intrathymic precursor T-cell proliferation, peripheral T-cell cycling, IL-7 plasma concentration and IL-7 receptor alpha chain (CD127) expression, different factors affecting naive T-cell homeostasis.