The present invention provides a novel cancer treatment method that shows significantly excellent anti-tumor effects and has fewer side effects. The present invention provides an antitumor agent, which is characterized in that the epitope 4 linking peptide and the immune checkpoint molecular modulator are administered in combination. Furthermore, by providing a cell that co-expresses human tumor antigen epitope peptide derived from SART2 and human HLA-A24, the antitumor effect on human can be evaluated.本發明提供一種顯示顯著優異之抗腫瘤效果且副作用較少之新穎癌症治療方法。本發明提供一種抗腫瘤劑，其特徵在於將表位4連結肽與免疫檢查點分子調節劑併用投予。又，藉由提供一種共表現源自SART2之人腫瘤抗原表位肽及人HLA-A24之細胞，能夠評估對人之抗腫瘤效果。
