Nassar, WaelEl-Ansary, MervatFayyad, TarekAbdel Aziz, Mostafa2016-06-202016-06-202016-01American Journal of Molecular Biology, 2016, 6, 1-11http://dx.doi.org/10.4236/ajmb.2016.61001http://hdl.handle.net/123456789/821Small non-protein coding micro-RNAs are regularly exported out of cells, both in health and disease. More than ninety percent of extracellular miRNAs are associated with lower-molecular-mass complexes bound to Argonaute 2 (Ago2), nucleophosmin-1 (NPM1) and high density lipoproteins (HDL), whereas the rest (~10%) are membrane-vesicle-encapsulated within exosomes, shedding microvesicles and apoptotic bodies. Regardless of the debate of the nature of circulating miRNA as byproducts of routine cell activities or mediators of cell-cell communication, proper understanding of the molecular behaviors of miRNA in health and disease, is expected to open a new gate for the discovery of new diagnostic tools and possibly therapeutic implementation in the near future.enExtracellular miRNAsExtracellular Vesicles (EVs)ExosomesHorizontal Gene Transfer (HGT)Microvesicles (MVs)Article