Interestingly, the increased TGFβ2 protein in the brain binds to the extracellular domain of Aβ precursor protein and activates a neuronal cell death pathway in AD, and the degree of TGFβ2-induced cell death is greater in cells that express a familial AD-related mutation in APP versus those that express the wild-type APP [26,47]. This evidence concerns the gene APP and Alzheimer disease.