IL5 and Crohn ileitis: The expansion of neutrophils in the BALF of SHIP-1−/− mice with ileitis coincided with a significant increase in the key neutrophil regulator G-CSF, while the expansion of eosinophils correlated with significant increases eosinophil regulators in BALF including eotaxin, IL-4 and IL-5 (Fig. 5C).