According to a study, a markedly higher number of eosinophils has been detected in the bronchoalveolar lavage fluid of patients with IPF.[48] Additionally, peptidyl-prolyl isomerase derived from eosinophils has been shown to enhance the stability of TGF-β mRNA, thereby contributing to the progression of pulmonary fibrosis.[49] Mast cells are also recognized as significant contributors to the progression of pulmonary fibrosis. Here, TGFB1 is linked to pulmonary fibrosis.