Towards the realization of clinical extracellular vesicle diagnostics: challenges and opportunities.

Extracellular vesicles (EVs) have been intensively researched in the last decade. As a result, many reports have revealed that disease-associated EVs can indeed be used as novel diagnostic tools to serve as a noninvasive 'liquid biopsy'. EVs are multi-molecular complexes and each molecule can be targeted for diagnostics. An increasing number of targetable molecules in EVs, such as miRNAs or proteins, have been identified and the accumulation of evidence will likely result in the identification of consensus EV markers. Also highlighted here are some advanced technologies that can be used as next generation assays. These technologies may overcome several challenges that continue to hinder the clinical use of EV diagnostics. A perspective is outlined for the potential contribution of EV research to develop diagnostic technologies for cancer and various other diseases.