GPC3 and hepatocellular carcinoma: We previously reported that MCT4+ HCC cases were mostly GPC3 positive [4], and in the double-positive cases, MCT4+ HCC cells may show circumferential membranous GPC3 immunoreactivity [4]; however, this trend of synergistic immunoreactivity in the double-positive HCC was less pronounced in subsequent detailed examination using serial sections of each case.