Compared to NC lung tissue (median 34.0%, range 25.6–51.7%), the ICAM–1 positive expression in type 2 pneumocytes of IPF alveolar tissue showed a significantly high percentage of type 2 cells in alveolar area (median 81.5%, range 56.3–98.8%, p < 0.0001) (Figure 4B). This evidence concerns the gene ICAM1 and idiopathic pulmonary fibrosis.