Mackay et al. (132) analyzed serum protein levels in neonates with and without NEC and showed that alpha-fetoprotein (AUC = 0.926), glucagon (AUC = 0.860), and IGHA1/IGHA2 (AUC = 0.826) could effectively distinguish NEC cases from non-NEC cases. This evidence concerns the gene GCG and necrotizing enterocolitis.