Additionally, many purinergic receptors (e.g., P2RX7, P2RY12 or P2RY13), which are important regulators of chemotaxis, phagocytosis, membrane polarization, and inflammatory signaling and thus emerged as possible microglial targets in AD (Calovi et al., 2019; Hemonnot et al., 2019), were found down-regulated in both AD mouse models. Here, P2RX4 is linked to Alzheimer disease.