TNF and autoimmune disease: Among the broad population of CD4+ T-helper cells, aging is associated with a predominance of Th2 (i.e., IL-4 and IL-10), and Th17-producing cells (i.e., IL-17-producing cells that are associated with autoimmune disease), whereas there is a decline in cells with a Th1 profile [i.e., IFN-gamma- and tumor necrosis factor-alpha (TNF-alpha)-producing cells] (183, 184).