F5 effectors reexpress IL-7R in vitro and in vivo. Histograms show IL-7R expression by control F5 T cells (solid line) compared with isotype control (gray fill) prior to stimulation ex vivo, after 24 hours of stimulation with NP68 peptide, following 72-hour peptide and further 96-hour culture with IL-2, and on day 1 and day 13 following adoptive transfer in vivo into Rag1^–/– hosts. Numbers indicate fold increase in mean fluorescence intensity (MFI) of IL-7R expression of F5 control T cells over the background of the negative control stain. Data are representative of at least 3 independent experiments.