Thus, CCL2 and MIP-1α are reported to mediate firm adherence and subsequent transmigration of neutrophils [44]; G-CSF and GM-CSF are growth factors that stimulate neutrophils to migrate across endothelial cells to sites of infection and inflammation [45]; KC/IL-8 appears to be a critical chemokine in neutrophil recruitment during lung infections [46] and BAL KC/IL-8 levels correlate strongly with neutrophil counts, disease severity, and poor clinical outcomes [47, 48]. This evidence concerns the gene CALCA and infection.