Among the common features of AD and diabetes, an etiological factor in AD is the reduced cellular reaction to insulin, a phenomenon highlighted in a post-mortem study when the causes and consequences of insulin resistance at the brain level were analyzed, especially regarding the hippocampus, the dentate gyrus, and the subiculum, favoring the emergence of a marked early pathology, with this insulin resistance of the brain being a frequent feature in AD patients [60]. The gene discussed is INS; the disease is diabetes mellitus.