To evaluate the conjugation efficiency of anti-GPC3 antibody to DOTA-Gd, and specific binding to GPC3- positive HCC cells, we first conjugated the commercially available mouse anti-GPC3 antibody (1G12) to DOTA-Gd at different molar ratios (5:1, 10:1, and 20:1, chelator: antibody). This evidence concerns the gene GPC3 and hepatocellular carcinoma.