Furthermore, the RAGE ligand S100A12 is released in patients with sepsis [17] and enhanced S100A12 concentrations have been shown in BALF from patients with acute lung injury and from healthy volunteers after LPS inhalation [34], but evidence that a functional s100a12 gene is not present in the murine genome [44] implies that RAGE-S100A12 ligation does not attribute to the host response to pneumonia in mice. Here, S100A12 is linked to pneumonia.