IL4 and colitis: In colitis, M1 macrophages that are polarized by interferon γ (IFNγ) or lipopolysaccharide (LPS) are associated with inflammation and gut destruction, whereas M2 macrophages that are polarized by IL4 have anti-inflammatory functions that are associated with tissue repair, which indicates that the modulation of macrophage polarization could be a therapeutic strategy for IBD [5].