CD4 and cancer: To determine which Treg-cell subpopulation is responsible for the increase of CD4+CD127lowFOXP3+ Treg cells in cancer patients, we determined the frequency of naïve, central, and effector memory cells within the Treg-cell compartment from healthy individuals, CRC, CLL, MGUS, and MM patients (Figure 5(a)) and compared these data with those previously described for CD4+CD25high Treg cells in healthy individuals as well as MGUS and MM patients [18, 23].