Upregulation of P2X7 receptors in human Alzheimer's diseased brains and in animal models has been reported (Parvathenani et al., 2003; McLarnon et al., 2006) and stimulation of P2X7 receptors on human microglia and macrophages increased the degenerative lesions observed in Alzheimer's disease. Here, P2RX7 is linked to early-onset autosomal dominant Alzheimer disease.