An inverse relationship between NEP levels and Aβ accumulation has been shown in temporal and frontal cortex (Hellstrom-Lindahl et al., 2008) and in the vasculature (Carpentier et al., 2002) of human AD patients as well as in the hippocampus of APP transgenic mice (Fukami et al., 2002), indicating that even a slight reduction in NEP levels for several decades can lead to increased Aβ levels. The gene discussed is APP; the disease is Alzheimer disease.