In cases of acute kidney injury (AKI) APN, along with other peptidases such as glutamyl- (E.C. 3.4.11.7), cysteinyl- (E.C. 3.4.11.3), and asparagyl amino peptidase (E.C. 3.4.11.21), is released to the urine. Here, LAP3 is linked to acute kidney injury.