In infants without NEC, the median (range) values of GFAP [0.30 (0.10–0.60) vs. 0.30 (0.10–1.30) P = 0.749] in the second sample were similar than those in the first sample, the median (range) values of GDNF [1.46 (0.85–2.24) vs. 1.56 (1.07–3.48) P = 0.114] in the second sample were lower than those in the first sample, and the median (range) values of FABP-2 [314.90 (184.70–521.60) vs. 294.20 (211.40–597.50) P = 0.741] in the second sample were higher than those in the first sample. The gene discussed is GDNF; the disease is necrotizing enterocolitis.