ACTA1 and pulmonary fibrosis: Immunohistochemical analysis revealed that a lot of type I collagen and α‐SMA positive myofibroblasts existed in bleomycin‐induced lung fibrosis (Figure 5G,I), whereas few type I collagen and α‐SMA positive myofibroblasts existed in that of the naftopidil treatment (Figure 5H,J).