The absence of a significant relationship between cognition and Iba1 in the dementia cohort with Alzheimer’s pathology is consistent with the hypothesis that microglia may lose their motility potentially as a result of (i) AD-related microglial dysfunction due to senescence [24, 25], (ii) immobilization of microglia around plaques [16, 26] and/or (iii) an immunosuppressed status of microglia preventing them responding appropriately to the pathological environment [15, 24, 27]. This evidence concerns the gene AIF1 and Alzheimer disease.