CLDN3 and necrotizing enterocolitis: Previous studies have shown that some biomarkers, including intestinal and liver fatty acid-binding protein, trefoil factor-3, fecal calprotectin, HBD2, HMGB-1, Claudin-3 and Relmβ, can be potential biomarkers for diagnosing NEC, and some of these markers may even indicate the severity of NEC to some extent (16–18, 28, 29).