It has been found that when DNA damage occurs in astrocytes, the serine at position 139 (S139) of H2AX is rapidly phosphorylated to produce γH2AX, while the level of γH2AX in astrocytes in AD susceptible regions (hippocampus and cerebral cortex) increases significantly, suggesting that there is a close relationship between H2AX phosphorylation in astrocytes and AD (Myung et al., 2008). The gene discussed is H2AX; the disease is Alzheimer disease.