TNF and allergic disease: The other type of MC mediators are the newly formed mediators, namely prostaglandin D2, leukotriene C4, leukotriene D4, platelet activating factor and cytokines, such as tumor necrosis factor α (TNF α), interleukin-4 (IL-4), interleukin-5 (IL-5), and interleukin-6 (IL-6), responsible for the late phase of an allergic reaction [47,67].