Western blotting results demonstrated that the Snail1, α-SMA, and Vimentin protein expressions in AECIIs of patients with sepsis-induced ARDS were upregulated markedly, while the expression of E-cadherin was lower than those of control group and pneumonia-induced ARDS group (P < 0.01). This evidence concerns the gene ACTA1 and susceptibility to pneumonia measurement.