We selected five genes after reviewing literature on methylation of intestinal wall derived genes previously reported to have a potential role in the development of NEC including erythropoietin (EPO) (11, 12), vascular endothelial growth factor A (VEGFA) (13–15), endothelial nitric oxide synthesis (ENOS) (16), defensin alpha 5 (DEFA5) (17), and toll-like receptor 4 (TLR4) (18–20). This evidence concerns the gene TLR4 and necrotizing enterocolitis.