NOS2 and necrotizing enterocolitis: To clarify whether succinate facilitates the polarization of NEC intestinal macrophages through SUCNR1, we detected the protein expression of SUCNR1 by western blot, observed the coexpression of the intestinal macrophage marker F4/80 with SUCNR1 by immunofluorescence, and analyzed the macrophage markers (iNOS and Arg1) and inflammatory factors (TNF‐α and IL‐10) via qRT‒PCR.