**4. Conclusion**

EVs are shed from the plasma membrane or released by endosomal pathways under both physiological and diseased conditions. Intercellular communication is one of the best known functions of EVs by far, which provides the possibility to utilize the EVs natural vehicle property of transporting nucleic acids, proteins, and lipids for drug delivery. Recent studies demonstrate that human RBCEVs can be developed as robust delivery platform for multiple therapeutic RNAs in cancer treatment. RBCEVs feature multiple benefits as compared to EVs from other cell types. They are easily obtainable in large amounts, can be frozen and thawed multiple times without significant compromise, are nontoxic and nonimmunogenic, can reach remote tissues in the body with minimal hindrance by physiological barriers, and do not contain DNA or other unpredictable contents which could result in horizontal gene transfer. By obtaining RBCEVs directly from the patient, they are safe to use allogeneic treatments and possess no risk of emerging mutations during expansion by cell culture. Thus, RBCEVs show promising advantages in overcoming various limitations of cell-based therapeutics. All in all, RBCEVs need further research in order to establish them as a new source and promising approach for practical therapeutics in clinical use.
