Interestingly, the mRNA expression levels of FOXP3 and cytotoxic T-lymphocyte antigen 4 (CTLA4) were up-regulated in R-NEC patients compared with A-NEC-XBP1u patients (Figure 4E and 4F), implying an enhanced immunosuppressive function in R-NEC patients. Here, CTLA4 is linked to necrotizing enterocolitis.