CD13 (or aminopeptidase N, APN) is a transmembraneglycoproteinwhose elevated expression in tumors is related to a major invasiveand metastatic behavior. The combinationthat could be given by the CD13 inhibition with the antiproliferativeand cytotoxic effects of HDAC inhibition could result in improvedefficacy in cancer treatment. Jia etal. This evidence concerns the gene ANPEP and cancer.