CXCL8 and necrotizing enterocolitis: Several pro-inflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and chemokines, including interleukin-8 (IL-8), were consistently observed to be increased in the circulation and intestinal tissues of infants with NEC and relevant animal studies.