Such a state is beneficial for fostering and sustaining a mutualistic relationship with the intestinal microbiota.210 In the context of NEC, there is an acute recruitment of blood monocytes to the damaged intestine, where they promptly differentiate into pro-inflammatory M1-type macrophages.211 Indeed, total and M1 macrophage populations were found to be increased in the intestinal tissue of NEC cases.212 M1 macrophages derived from both human NEC patients and animal models demonstrate elevated expression of Smad7. Here, SMAD7 is linked to necrotizing enterocolitis.