With regards the involvement of P2 receptors in this pathology, an up-regulation of the P2X7 receptor occurs around Aβ plaques in a mouse model of AD (Parvathenani et al., 2003) and enhanced P2X7 expression is detected in brain samples from AD patients, especially in microglia associated with Aβ plaques (McLarnon et al., 2006). The gene discussed is P2RX7; the disease is Alzheimer disease.