The expression of GPC-6 had a significant impact on the OS in Caucasians and sorafenib-treated HCC subgroup (HR = 0.59, 95% CI = 0.36–0.97, P = 0.0364; HR = 0.15, 95% CI = 0.04–0.56, P = 0.0012, Supplemental Table 2, 3). Here, GPC6 is linked to hepatocellular carcinoma.