 This study evaluated the safety and efficacy of mesenchymal stromal cell, master of science, therapy and its derived extracellular vesicles, EVs, in patients with severe COVID-19. The results showed that MSCs and their EVs were safe and effective in reducing inflammatory markers in patients with COVID-19. This suggests that MSCs and their EVs may have potential therapeutic applications in treating COVID-19. This article was authored by Morteza Zarabi, Mohamed Ameen Shahbaf, Massa Maiman Nori, and others.