IL4 and Alzheimer disease: In particular, the predominance of type 2 helper T cell (Th2)-mediated immune responses represents a hallmark feature of AD, driving chronic inflammation through the overproduction of cytokines [e.g., interleukin (IL)-4, IL-5, and IL-13] and contributing to immunological changes such as eosinophilia and elevated serum IgE levels [5].