Furthermore, a list of 19 plasma biomarkers clinically used in non-invasive HCC diagnosis was also investigated [16] and the results were shown in Fig. 5d: GLUL was significantly up-regulated in C2 subtype, while EPCAM (epithelial cell adhesion molecule) and AFP were significantly up-regulated in C1 subtype, which results were concordant with a recent study [32] and suggested that abundance of these genes in plasma of HCC patients might inform their subtypes. Here, EPCAM is linked to hepatocellular carcinoma.