CD28 and renal carcinoma: The frequencies of four effector T cell subsets, namely CD4+IFNγ+, CD8+IFNγ+, CD4+IL17+, CD8+IL17+ T lymphocytes, and two Treg subsets, CD4+CD25hiCD127lo and CD8+CD28-CD127loCD39hi Treg, were comparatively analyzed in the peripheral blood of bladder and renal cancer patients.