Given that Aβ plays a predominant role in the preclinical, prodromal, and dementia stages of the disease [14] and positron emission tomography (PET)-Aβ imaging (measured by Centiloid [CL]) provides the most accurate diagnosis of AD [15], the performance of P2X7, CD11b, and CD11c were compared by PET-Aβ status (−ve: ≤25 CL/+ve: >25 CL), followed by further comparisons by symptoms(cognitively normal [CN] −ve, CN +ve, mild cognitive impairment [MCI] −ve, and dementia [MCI +ve and AD]). The gene discussed is ITGAX; the disease is dementia.