FOXP3 and infection: Even though the frequency of Foxp3+ Treg cells (Figs 4G, 4H and S5G) within the MLNs in Sm-infected Foxp3cre IL-4Rα−/lox mice were similar to littermate controls at 8 wk post infection, Foxp3 surface expression level on a per-cell basis was, however, dramatically reduced in Sm-infected Foxp3cre IL-4Rα−/lox mice compared to infected littermate controls (Figs 4I and S5H).