While Th1 and Th2 cells secrete different cytokines, the Th1 cells are reliant on interlukin-2 (IL-2), interferon-γ (IFN-γ), and tumor necrosis factor (TNF), which are involved in cell-mediated immunity against pathogens, and the Th2 cells are mostly dependent on interleukin-4 (IL-4) and interleukin-5 (IL-5), which stimulate the production of IgE antibodies and eosinophil responses, resulting in the allergic diseases [10, 11]. The gene discussed is IL5; the disease is allergic disease.