CD4 and kidney transplant: Both the percentage of CD4+CD127low+/−FoxP3+-Treg cells of CD4+-T cells and their composition with four distinct Treg cell subsets were determined in the circulation of healthy non-transplanted volunteers (Group A), stable kidney transplant patients (Group B) and kidney transplant patients with biopsy proven rejection (BPR) (Group C), (Table 1, Figure 1).