TNF and necrotizing enterocolitis: Figure 4 shows that the secretion of HMGB1 (Figure 4(a)), IL-1β (Figure 4(b)), IL-6 (Figure 4(c)), IL-8 (Figure 4(d)), and TNF-α (Figure 4(e)) was significantly lower in the NEC+butyrate and control groups than in the NEC group. However, the production of IL-10 (Figure 4(f)) was significantly increased (P < 0.05).