APP and early-onset autosomal dominant Alzheimer disease: The TGF-βs are involved in a variety of brain responses to prevent the disruption of homeostasis, including the inflammatory response, microglial activation, astrocytosis, extracellular matrix production, the accumulation and distribution of amyloid beta, the regulation of factors associated with potential Alzheimer’s disease risk (APP, ApoE, α-MAC, COX-2), and the inhibition of cell death.