Applying a modern proteomic approach Nguyen et al. [19] identified a proteomic “signature” that discriminated VAP(+) from VAP(−) patients in Acute Lung Injury patients: it is constituted by three BAL proteins: S100A8, lactotransferrin (LTF), and actinin 1 (ACTN1). Here, LTF is linked to ventilator-associated pneumonia.