CD4 and B-cell chronic lymphocytic leukemia: We detected a significant downregulation of CD127 mRNA expression in CD4+CD25high T cells from healthy donors (n = 5) as well as CLL patients (n = 5, P < 0.05, Figure 1(a)) by quantitative PCR indicating that CD127 expression might also be used to specifically identify CD4+FOXP3+ Treg cells in cancer patients.