PROBLEM TO BE SOLVED: To provide a new protein targeting an immune checkpoint molecule such as PD-1. A fusion polypeptide comprising a cell membrane-permeable peptide, a DNA-binding peptide that binds to the base sequence of PD-1 (Programmed cell death 1) gene, and a peptide having DNA methylation activity. [Selection diagram] None【課題】PD-1等の免疫チェックポイント分子を標的とする新たなタンパク質の提供。【解決手段】細胞膜透過性ペプチド、PD-1(Programmed cell death 1)遺伝子の塩基配列に結合するDNA結合ペプチド及びDNAメチル化活性を有するペプチドを含む融合ポリペプチド。【選択図】なし