IL6 and Infertility: Cytokines like interleukin 1β (IL-1β), IL-6, IL-10, IL-18, tumor necrosis factor α (TNF-α), interferon g (IFN-g), and transforming growth factor β1 (TGF-β1) are notably elevated in idiopathically infertile males and those with varicocele (65, 66).