Among the tested biomarkers—which included fecal calprotectin, lysozyme, haptoglobin and intestinal alkaline phosphatase, which were previously found to be indicative of NEC near diagnosis time [36,37,38,39] and lipocalin-2, a key marker associated with the mucosal samples of NEC infants [40]—only the calprotectin and lipocalin-2 combination was found to provide a predictive signature for NEC development up to a week in advance of the diagnosis. This evidence concerns the gene LYZ and necrotizing enterocolitis.