TH2 cells produce cytokines that are associated primarily with the production of antibodies, especially lgF, that are important in allegic reactions ( see the discussion of hypersensitivity on page 523). They are also important in the activation of the eosinophils that defend against infections by extracellular parasites such as helminthes (see Figure 17.15 on page 491). Animation: Antigen Processing and Presentation Steps. www.microbiologyplace.com