CA9 and necrotizing enterocolitis: When comparing gene expression within PanCK+ ROIs of cardiac and classical NEC ileum, DEGs (Figures 4A and S11B) used to construct the largest PPI subnetwork (Figure 4B) mapped functionally to immune chemotaxis, immunoglobulin A (IgA) production, interleukin 10 (IL-10) signaling, erythrocyte metabolism, and carbonate dehydratase activity (Figure 4C), the latter involved in regulation of cellular pH.