ACTA1 and pulmonary fibrosis: Similar to the bleomycin model of pulmonary fibrosis [33], we observed reduced type I collagen lung mRNA expression (Figure 8C), correlating with markedly less αSMA+ staining in the lung tissue of RELMα–/– mice relative to wild-type mice (Figure 9F), suggesting that knockout mice were partially protected from this particular fibrotic phenotype, and that RELMα may participate in myofibroblast accumulation.