GPC3 and hepatocellular carcinoma: When we classified these 36 HCCs into well, moderately, and poorly differentiated tumors, positive staining for either GPC3 or IGF-1R was only observed in moderately and poorly differentiated HCC (Figure 1E), and therefore the expression of GPC3 and IGF-1R was correlated with tumor grade (p < 0.05 by Pearson's Chi-Squared test).