CD4 and benign prostatic hyperplasia: CD4+ CD28− T cells expand in several diseases associated with chronic inflammation (e.g. autoimmunity, atherosclerosis, etc)16.The increased amount of CD4+ CD28− T cells in patients with BPH/LUTS-ED, which can secrete inflammatory cytokines such as interferon-γ (IFN-γ) and tumor necrosis factor-α (TNF-α), could be promoting the differentiation of CD4+ T cells to IL-17 producers, process in which TGF-β and IL-6 are involved, and that is amplified by TNF-α and IL-1β21.