NECTIN4 and neoplasm: The newly discovered oncolytic MV receptor and tumor marker Nectin-4 is selectively overexpressed and identified as an important therapeutic target for primary and metastatic triple-negative breast cancers as well as for lung, bladder, and pancreatic cancers [14,16,17,39,40,41], which makes Nectin-4-specific oncolytic MV a crucial novel tool in targeting Nectin-4-positive breast cancer and other adenocarcinomas.