CD38 and early-onset autosomal dominant Alzheimer disease: CD38+ or CD157+ microglial cells are present at the loci of neuroinflammation, being activated by various DAMPs and PAMPs; beta-amyloid induces CD38 expression in microglia in the aging brain [152], and a higher prevalence of CD38- and CD157-expressing microglia was found in olfactory bulbs of animals with the experimental model of Alzheimer’s disease [153].