That said, it is still very interesting to note that the cells from the rapidly progressing IPF patients do have enhanced responses to PDGF (proliferation, migration) and TGFβ (contraction, cytokine production), whereas these responses are not as profoundly altered in fibroblasts from slowly progressing IPF patients relative to the non-IPF controls (Budd et al, under review). The gene discussed is TGFB1; the disease is idiopathic pulmonary fibrosis.