FNDC5 and acute respiratory distress syndrome: Irisin enhances the expression of the autophagy protein light chain 3-II in particulate matter less than 2.5 μm in diameter (PM2.5)-induced ALI and decreases the expression of p62 protein, which promotes autophagy and decreases the expression of proinflammatory factors such as tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-18 (Ma et al., 2023).