CCR5 and Alzheimer disease: Consistent with the effect of CCR5 gene knock-out, the CCR5 antagonist DAPTA decreased microglia and astrocyte activation in the hippocampus, along with reducing the number of cells expressing NF-κB protein, a key player in pro-inflammatory cytokine signaling pathways, in a neuroinflammatory rat model of AD (Figure 3) (57).