TGFβ1 significantly promoted fibroblast to myofibroblast transition in IPF cells at 24 h, as shown by increased α-smooth muscle actin (αSMA) (Fig. 3c), and pre-treatment with nintedanib attenuated this effect in a dose- and donor-dependent manner. This evidence concerns the gene ACTA1 and idiopathic pulmonary fibrosis.