As CD25 is not solely expressed on Treg cells but also on activated conventional CD4+ T cells, and the downregulation of CD127 expression in CD4+CD25high FOXP3+ Treg cells from healthy donors has been reported [5, 6], we first assessed if CD127 downregulation is also apparent in CD4+CD25high Treg cells from cancer patients. This evidence concerns the gene CD4 and cancer.