Fig. 1: The expression and clinical significance of GDF1 in HCC.

a The relative mRNA expression of GDF1 was detected by qPCR in the HKU cohort, which included 83 HCC tissues and their paired nontumor liver tissues (two-tailed paired-sample t-test, data are presented as mean values ± SD). b The relative mRNA expression of GDF1 was measured by qPCR in the TCGA cohort, which included 373 HCC patients and 50 paratumor liver tissues (two-tailed independent Student’s t-test, data are presented as mean values ± SD). c The relative expression of GDF1 at the protein level was measured by western blot in representative HCC tissues and their paired nontumor liver tissues (n = 3 independent experiments). d IHC staining of GDF1 in representative HCC tissue and paired nontumor liver tissue (n = 3 independent experiments). e The relative mRNA expression of GDF1 was measured by qPCR in subgroups of patients with different tumour grades in the HKU cohort (one-way ANOVA, data are presented as mean values ± SD) f and in the TCGA cohort (one-way ANOVA, data are presented as mean values ± SD). g IHC staining of GDF1 in representative poor-, moderate-, and well-differentiated HCC tumours in a tissue microarray (TMA) containing 196 liver tumour tissues. h, i Kaplan–Meier analysis indicated that the high expression of GDF1 was significantly correlated with poor overall survival (h) and disease-free survival (i) of HCC patients (log-rank test). j The expression of GDF1 was examined in a panel of normal tissues from the GTEx database (17,382 RNA-seq across 54 tissue sites and two cell lines). Boxes represent quartiles, centre lines denote 50th percentile, and whiskers extend to most extreme values. Scale bars represent 20 µm. Source data are provided as a Source Data file.