As a primary Aβ-degrading enzyme, CD10 is downregulated in the early stages of AD, corresponding with increased Aβ accumulation in the brain and the formation of amyloid-like structures (Yasojima et al., 2001; Nalivaevaa et al., 2004; Madani et al., 2006; El-Amouri et al., 2008). This evidence concerns the gene MME and Alzheimer disease.