In a multidrug-resistant Pseudomonas aeruginosa-induced ALI mice model, MSC-derived extracellular vesicles modulated the balance between pro-inflammatory and anti-inflammatory macrophages by inhibiting the activity of the NF-kB signaling pathway, leading to the downregulation of the pro-inflammatory macrophage markers iNOS and IL-12 and the upregulation of the anti-inflammatory macrophage markers Arg-1 and IL-10; these effects reduced the bacterial load and inflammatory response, resulting in decreased mice mortality (145). The gene discussed is ARG1; the disease is acute respiratory distress syndrome.