IL4 and hand, foot and mouth disease: However, some proinflammatory factors in the serum or central cerebrospinal fluid have been reported to be significantly increased in EV71-induced HFMD, including interleukin (IL)-4, IL-5, IL-22, IL-23, IL-2, tumor necrosis factor (TNF)-α, IL-1β,[1] and IL-6.[4] These findings indicate that the inflammatory process is involved in the pathogenesis of HFMD.