TGFB1 and pulmonary fibrosis: Furthermore, the expression levels of VEGF, FGF, and TGF-β mRNA were determined by qRT-PCR during the development of bleomycin-induced pulmonary fibrosis; we also found that mRNA levels of VEGF, FGF, and TGF-β were increased in the modeling group but decreased in the control group (Figure 3D).