BECN1 and pulmonary fibrosis: To clarify if BECN1 has similar effects in the pathogenesis of silica-induced pulmonary fibrosis, and if miR-1224-5p interferes with these effects by targeting BECN1, fibroblasts were transfected with miR-1224-5p inhibitor alone or with BECN1 siRNA, then treated with 2 ng/mL TGF-β1 for 48 h.