Melphalan flufenamide (Melflufen), a peptidase enhanced cytotoxic derivative of melphalan with targeted delivery of melphalan via membrane bound aminopeptidase N (APN or AD13) [113], has demonstrated favorable in vitro and ex vivo effects on high risk multiple myeloma cell lines with del17p and TP53 mutations [114]. The gene discussed is ANPEP; the disease is plasma cell myeloma.