Novel therapeutics based on extracellular vesicles (EVs) recently passed a critical development milestone. During 2020, some of the first experimental EV products developed by biopharmaceutical companies entered human clinical trials (1–3). EVs are nanometer-sized, lipid-wrapped spheres released by almost every cell type in the human body. EVs are loaded with a cargo of proteins, lipids, and RNA, and they are tagged with surface markers that favor uptake by target cells. Thus, EVs are a key mode of cell-to-cell communication (4).…