ACTA1 and pulmonary fibrosis: Moreover, in a severe form of pulmonary fibrosis induced by intratracheal injection of bleomycin that caused a 100% mortality, the injection of LAP-CST or LAP-L1L2-CST did not improve survival rate (Figure 6b) or the histopathological score and fibrotic markers in lung parenchyma, which showed marked thickening of the alveolar septa, almost devoid of alveolar space, extensive areas of pulmonary parenchyma obliteration (with more than 60% of lung occupied by dense fibrosis) (Figure 6c), and presence of αSMA-expressing myofibroblasts in peribronchiolar dense fibrotic areas (Figure 6d).