Moreover, given the increased numbers of fibroblasts in IPF tissue [1], the elevated levels of TGFβ [38], and the ability of this cytokine to drive epithelial to mesenchymal transition [39], these findings may explain the higher expression of IL-33 reported in the lung tissue of IPF patients [13, 14]. Here, TGFB1 is linked to idiopathic pulmonary fibrosis.