ICAM-1 mRNA expression in the cells pretreated with vehicle did not differ from the mRNA expression in the untreated cells prior to infection (the relative amount of ICAM-1 mRNA compared with the untreated cells: 1.02 ± 0.07 in the HTE cells and 1.04 ± 0.08 in the HNE cells, n = 3, P > 0.30). Here, ICAM1 is linked to infection.