Similar studies showed that matrix stiffening synergizes with TGF-β1 to promote mRNA expression of both col1a1 and mmp1 in IPF-fibroblasts, whereas TGF-β1 and matrix rigidity downregulate mmp1 in normal pulmonary fibroblasts [9]. Here, TGFB1 is linked to idiopathic pulmonary fibrosis.