Because the expression of ICAM-1 was enhanced in the initial phase of inflammation and early phase of acute respiratory distress syndrome (Schütte et al. 1996; Pugin et al. 1996; Kuppner et al. 1990), sICAM-1 levels may also rise in the early phase of acute exacerbation of IPF. Here, ICAM1 is linked to acute respiratory distress syndrome.