SMN1 and pulmonary fibrosis: In a single study, the administration of sodium butyrate (10 mg orally five times a week over four weeks or 2 mg subcutaneously five times a week for two weeks) in a bleomycin mouse model with dermal and lung fibrosis reduced the expression of alpha-smooth muscle actin (SMA) in the skin (a myofibroblast marker), reduced collagen deposits and skin thickness, suppressed macrophage proliferation, reduced the expression of profibrotic and pro-inflammatory genes in the fibrotic skin, and reduced SMA protein in the fibrotic lung tissue [84].