IL17A and necrotizing enterocolitis: The mRNA expression levels of RAR-related orphan receptor C (RORC) and interleukin 17A (IL17A) were down-regulated in A-NEC-XBP1s patients compared with A-NEC-XBP1u patients (Figure 4C and 4D), demonstrating that there were less Th17 cells in A-NEC-XBP1s patients.