Intratumoral injection of HLA-A*02:01-restricted GPC3144–152 peptide-specific CTLs alone against GPC3-expressing tumors, SK-Hep-1/GPC3 and HepG2, was only partially effective, suggesting that the HLA-A*02:01-restricted GPC3144–152 peptide endogenously presented on SK-Hep-1/GPC3 and HepG2 tumor cells was not sufficiently dense. This evidence concerns the gene GPC3 and neoplasm.