More recently, Neprilysin-2 (NEP2), which has been demonstrated in vivo to control Aβ levels by cleaving Aβ between amino acids Val18 and Leu17 similar to ECE-1 (Huang et al., 2008), is reduced in association with AD (Huang et al., 2008, 2012; Hanson et al., 2010; Hafez et al., 2011). Here, MMEL1 is linked to Alzheimer disease.