Decreases in NEP mRNA, protein level, and activity are observed in the postmortem AD hippocampus (Yasojima et al., 2001; Caccamo et al., 2005; Wang et al., 2005), and NEP protein expression is inversely correlated with the severity of Aβ accumulation and cognitive impairment (Wang et al., 2010). This evidence concerns the gene MME and Alzheimer disease.