GDF15 and fibrosis: As shown in Supplementary figure 1, these results were remarkably similar to those obtained for ≥F2 fibrosis [AUROC 0.762 (95% CI 0.64–0.89), p < 0.0001, optimal cut-off of serum GDF-15 1193.7 pg/ml; sensitivity 63.6%, specificity 83.1%, PPV 53.8% and NPV 88.1%].