For example, the interactions between a well-known risk factor of AD risk apolipoprotein E gene ε4 and IL-8 gene locus, IL-8 gene –251T>A, and IL-1α gene -899C>T variants have been reported to influence the susceptibility to AD.[24] Additionally, gene–environment interactions may be involved critically in the development of AD, which should be considered for the association as well. Here, APOE is linked to Alzheimer disease.