The positive expression rate of TRAF6 protein was 49.7 % (85/171) in HCC tissues, significantly higher than para-carcinoma liver tissues (36.3 %, P = 0.012), cirrhosis tissues (21.6 %, P = 0.002), and normal liver tissues (12.1 %, P < 0.001, Table 1, Fig. 1). Here, TRAF6 is linked to hepatocellular carcinoma.