Studies have found a relative risk of about 1.9 to 2.3 of developing Alzheimer’s disease (AD) for individuals with diabetes (Leibson et al., 1997; Ott et al., 1996; Ronnemaa et al., 2009), and this risk can increase up to 5.5 in the presence of ApoE4, a risk factor for AD (Peila et al., 2002). The gene discussed is APOE; the disease is Alzheimer disease.