The results of the further analysis indicated that autoantibody to GNAS can not only distinguish 46.1% of AFP (−) HCC patients from normal controls but also has a stronger ability to distinguish early HCC patients (62.4%) from normal controls than its ability to distinguish late HCC (51.5%) from normal controls (Figure 4B,F), which can supplement AFP in the diagnosis of HCC. Here, AFP is linked to hepatocellular carcinoma.