MIF and bacterial infectious disease: According to pathway analysis, the biological pathways that were significantly up-regulated in the TRAIN individuals after training (p <0.001) were those involved in inflammatory and immune response, including migration inhibitory factor (MIF) in innate immunity response (p = .00014), bacterial infections in normal airways (p = .0002), apoptosis and survival Nitric Oxide synthesis and signaling (p = .0002) and bacterial infections in CF airways (p = .0002) (data not shown).