Consistent with our results, other authors showed a lower PDGFA expression in IPF patients vs. healthy subjects [37], decreased serum levels of PDGF-AA in patients with IM vs. healthy subjects [38] and explained the important role of TGF-β in both IPF [39,40,41] and IM [42,43]. Here, TGFB1 is linked to idiopathic pulmonary fibrosis.