TGF-β has been shown to modulate a wide range of processes that are implicated in AD, including brain injury response and astrocytosis, brain inflammatory response and microglial activation, extracellular matrix production, accumulation and regional distribution of amyloid, regulation of known or potential AD risk factors (e.g., APP, COX-2), and inhibition of cell death. The gene discussed is APP; the disease is Alzheimer disease.