TGFB1 and idiopathic pulmonary fibrosis: In line with its key role in fibrogenesis, in the microarrays we found the expression of TGFβ1 to be significantly increased in the invading fibroblast fraction and moreover, also predicted to be associated with the generated functional gene clusters ‘IPF’, ‘invasion of cells’, and ‘metastasis’ in the in silico gene cluster analysis (Fig. 3C).