TGFB1 and pulmonary fibrosis: This response was also verified in a fibrosis model of NIH/3T3 cells and human embryonic lung fibroblast MRC-5 cells stimulated by TGF-β in vitro, and the research demonstrated that miR-449a alleviated pulmonary fibrosis and promoted fibroblast autophagy by inhibiting its target, Bcl2 [83, 84, 110].