The percentage expression of ICAM–1 significantly upregulated in the small airway epithelium in IPF lung tissue (median 16.3%, range 9.56% to 68.5%) compared to NC lung tissue (median 3.76%, range 1.17–14.1%, p < 0.0001) (Figure 4B). Here, ICAM1 is linked to idiopathic pulmonary fibrosis.