TLR4 and necrotizing enterocolitis: Germ-free mice have been observed to possess an immature intestinal capillary network when compared to animals with functional microbiota.255 However, intestinal mucosal damage, a critical event in the pathogenesis of NEC, enables bacterial translocation into the mesenteric microvasculature.256 This process triggers a cascade of interactions, notably with TLR4 on endothelial cells.