ANPEP and cancer: Zn-dependent metalloproteases, such asmatrix metalloproteases (MMPs) and cell membrane-bound proteases, e.g., aminopeptidase N (APN), angiotensin converting enzyme (ACE) and neutral endopeptidase (NEP), are examples of enzymes involved in cancer development and reported to be inhibited by αAPs [3,4,5,6,7,8].