NOS2 and acute respiratory distress syndrome: Figure 6F shows that cryo-MenSCs treatment favoured a reduction in iNOS expression levels compared with those in the ARDS-RL group at day 2 and an increase in Arg1 levels at day 7 (Figure 6G). Both molecules are indicative of pro- and anti-inflammatory macrophages M1 and M2-like, respectively (Orecchioni et al., 2019).