Taken together, our data on human frontal cortex postmortem tissue indicate that neither the increase in microglial numbers nor microglial DKK2 upregulation, both of which were evident in mouse models, occur in human brains under conditions classified as “pathologic aging” and “AD.” However, microglia did exhibit clustering behavior around βAmyloid plaques although this was not linked to DKK2 expression. Here, DKK2 is linked to Alzheimer disease.