TGFB1 and idiopathic pulmonary fibrosis: TGFβ1, a crucial cytokine in IPF, was found to induce the expression of collagen (COL1), smooth muscle actin (α-SMA), and fibronectin (FN) in myofibroblasts, leading to their secretion and deposition in the extracellular matrix (Fig. 8B–E).