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). Here, CD4 is linked to medical procedure.