TLR4 and necrotizing enterocolitis: There have been numerous attempts to identify candidate markers of gut injury that discriminate NEC from other inflammatory conditions.44,45,46,47,48 Animal NEC models suggest that the immune dysregulation and microbial dysbiosis associated with severe NEC are tandem host-bacterial missteps owing to excessive toll-like receptor 4 signaling in response to bacterial LPS.19,49,50,51,52 The majority of candidate NEC biomarkers are proteins further downstream from the initial host signaling steps.