Unlike the protease and matrix protein gene sets that were consistently up-regulated in all of the IPF patient data-sets, the TGFβ up-regulated gene set (comprised mainly of positive regulators of the TGFβ pathway) was only enriched in the IPF patients who had experienced an acute exacerbation compared to non-IPF control subjects, possibly indicating its importance in active disease. Here, TGFB1 is linked to idiopathic pulmonary fibrosis.