Assessment of the clustering of specific EMT-related genes led to the observation that GSK3b, COL3A1, SPARC and COL1A1 all correlated with CD44 and VIM in normal lung biopsies, but not in rapid IPF lung biopsy samples or in slow IPF lung tissue (Figure 2). This evidence concerns the gene COL1A1 and idiopathic pulmonary fibrosis.