CD4 + CD25 + CD127lo/- T cells express the majority of high level Foxp3 protein. PBMCs were isolated and stained for flow cytometry as described in the methods section. Lymphocytes were gated using forward and side scatter profiles followed by CD3 and CD4 gating. A. Within this defined gate, CD127 and CD25 staining was determined using fluorescence minus one (FMO) controls. One representative subject is shown out of 159 assayed with the percentage of each population in upper right corner. B. Foxp3 staining was determined using an isotype control. The percentage of Foxp3 staining within each defined quadrant is plotted for the entire cohort (mean% of Foxp3+ cells within CD3 + CD4 + CD25 + CD127lo/-: 71.1%; SD 14.7%). The CD127 + CD25+ T cells have a subset of low expressing Foxp3+ cells (mean% of Foxp3+ within the CD3 + CD4 + CD25 + CD127+: 20.8%; SD 11.1%). C. Mean Fluorescent Intensity (MFI) for Foxp3 is shown. CD25 + CD127lo/- cells display the highest amount of Foxp3 per cell. The mean MFI for Foxp3 in CD3 + CD4 + CD25 + CD127lo/- T cells: 377 SD 137.8 vs. CD3 + CD4 + CD25 + CD127+ T cells: 146 SD 49.4.