Although increased mRNA levels of COL1A1 and ACTA2 were detected in cultured lung fibroblasts from IPF compared to control patients (Additional file: Fig. S1A, B), their protein levels and that of transforming growth factor-beta receptor 1 (TGFBR1) were higher in most cases in fibroblasts from control compared to IPF patients (Additional file: Fig. S1C, Table 1). This evidence concerns the gene COL1A1 and idiopathic pulmonary fibrosis.