IL4 and Alzheimer disease: The co-localization of Iba-1/TNF-α, Iba-1/IL-1β, and Iba-1/IL-4 confirmed that TNF-α, IL-1β, and IL-4 were mainly expressed in clustered microglia in AD and KOAD mice, suggesting that the majority of TNF-α, IL-1β, and IL-4 are produced by microglia.