There were many reasons found recent years why the sensitivity was low in the diagnosis of HCC by 18F-FDG PET/CT, the most popular theory was that the low hexokinase activity and high glucose-6-phosphatase activity in well-differentiated HCC tumors, and resulting in the uptake of 18F-FDG by HCC lesion similar to that of normal liver parenchyma [7], however, this theory could not take into account the moderately differentiated HCC (accounts for a considerable proportion of HCC). Here, G6PC1 is linked to hepatocellular carcinoma.