Through direct interaction with AECs, GM-CSF also improves epithelial repair processes (Cakarova et al., 2009), with preclinical data suggesting that GM-CSF may ameliorate lung injury and respiratory failure through limiting early epithelial injury and maintaining AM function (Huffman Reed et al., 1997; Paine et al., 2001; Paine et al., 2003). This evidence concerns the gene CSF2 and respiratory failure.