NFKB1 and necrotizing enterocolitis: The Reactome pathways, such as signaling by the B Cell Receptor (BCR), immunoregulatory interactions between a lymphoid and a nonlymphoid cell, FCERI-mediated NF-κB activation, antigen activates B Cell Receptor (BCR) leading to generation of second messengers, and CD22 mediated BCR regulation, were significantly enriched by the upregulated genes (Figure 1(b), adjusted P value < 0.05), suggesting that the dysregulation of immune system was a major hallmark of NEC.