ACTA1 and acute respiratory distress syndrome: Consistently, the mRNA levels of fibrogenesis-related genes such as α-SMA, Collage I, Fibronectin, Tmp1, Tgf-β, and Pdgft-β were down-regulated in PP2Acα cKO ALI model mice (Fig. 5K–N, Fig. S5A, B) Thus, it is clear that PP2Acα deficiency in hepatocytes reduces the extent of liver damage in ALI model mice.