PPARG encoded peroxisome proliferator-activated receptor γ (PPARγ), and the antifibrotic effect of PPARγ has been found to be manifested by inhibiting TGF-β expression and blocking downstream signal transduction after ligand activation.[71] Furthermore, Metformin induced adipose differentiation in myofibroblasts by upregulating BMP2 and activating PPARγ.[72] These results indicate the progression of negative regulatory fibrosis by activation of PPARγ and suggest that this receptor may be a key target for the treatment of IPF. The gene discussed is TGFB1; the disease is idiopathic pulmonary fibrosis.