This suggests that exogenous TG2 is acting via induction of TGFβ signalling which is supported by the finding of a 70% increase of active TGFβ in the culture medium of TG2 treated IPF cells measured using the Mink lung epithelial cells (MLECs) reporter system (Fig. 4g) and the presence of increased active TGFβ in the matrix of TG2 treated NHLFs (Fig. 4c). This evidence concerns the gene TGM2 and idiopathic pulmonary fibrosis.