These reactive astrocytes and activated microglia may produce nitric oxide and inflammatory cytokines (such as interleukins, TNF-α, and TGF-β) that could contribute to a reinforced neuroinflammation cascade, which may amplify the initial neurotoxic insults triggered by tau overexpression to drive neurodegeneration and further brain pathologies of AD. This evidence concerns the gene TGFB1 and Alzheimer disease.