TNF and acute respiratory distress syndrome: Compared with unmodified MSCs, administration of BM-MSCs overexpressing HO-1 further reduced lung injury, edema, neutrophilia, and levels of IL-1β and TNF-α, but increased levels of HGF, KGF, and IL-10 in serum and lung tissue, and improved the 7-day survival rate in experimental LPS-induced ARDS (Chen et al., 2019).