PTGS2 and necrotizing enterocolitis: As a COX-2 selective inhibitor,(0.5 mg/kg, 1 mg/kg and 1.5 mg/kg) in this study led to a weight increase in NEC model rats, reduced NEC incidence and mortality, and alleviated ileum histopathology, suggesting that a low dose of celecoxib can inhibit the development of NEC and play a protective role in NEC-related deaths, which was consistent with the finding of a previous study [22].