AD emerged as the T helper 2 (Th2) disease, and this is supported by multiple observations, including increased levels of cytokines and chemokines secreted by Th2 cells, such as interleukin 4 (IL-4), IL-5, IL-13, CCL17, CCL18, and CCL22 [10,11,12]. The gene discussed is IL4; the disease is Alzheimer disease.