CD9 and pancreatic neoplasm: Through our ELISA assay we measured levels of different exosome populations, in particular those carrying the ubiquitous CD9, CD81 and some markers already found in tumour exosomes of pancreatic cancer such as CD44v6, Tspan8, EpCAM, CD24, CXCR4, Integrins α6 and β4, CD133.