As shown in Table 1, patients with fibrosis/cirrhosis (METAVIR stage F1–F4, N = 318) had higher serum GDNF (sGDNF) levels (28.4 pg/ml (IQR: 26.2, 31.6)) than patients without fibrosis (11.6 pg/ml (IQR: 7.2, 21.1)) (healthy controls and METAVIR stage F0, N = 376) (p < 0.001). Here, GDNF is linked to fibrosis.