Ready-to-use ELISA kits are available for the detection of Ly51, an alias of the protein, glutamyl aminopeptidase. The official gene symbol is ENPEP. The protein, with a mass of 109.2 kDa and length of 957 residues, is reported to be membrane-associated. It is a member of the Peptidase M1 family and may be known by other names, including: gp160, APA, differentiation antigen gp160, aminopeptidase A, and AP-A.