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). Here, RETNLB is linked to necrotizing enterocolitis.