In addition, loss of autophagy in macrophages has been reported to promote inflammation through increased pro-inflammatory M1 and decreased anti-inflammatory M2 polarization.42 Autophagy induced by anti-tumor necrosis factor (TNF) antibodies promotes M2 polarization in macrophages suggesting that macrophage autophagy may have a repressive role in IBD.43 Taken together, these findings show that macrophage autophagy can inhibit inflammatory diseases, such as colitis, by regulating inflammatory cytokines and influencing macrophage polarization and microbial killing (Fig. 4a). Here, TNF is linked to colitis.