PROBLEM TO BE SOLVED: To provide more excellent methods of modifying the function of Fc region, wherein the binding to FcγR is optimized.SOLUTION: The present invention provides a hetero dimerization polypeptide comprising an Fc region where the function of the Fc region is improved by producing a hetero dimerization polypeptide having an Fc region consisting of two polypeptides in which amino acid sequences are different (a first polypeptide and a second polypeptide), as compared with a homo dimerization body where the Fc region consists of a first polypeptide only or a homo dimerization body where the Fc region consists of a second polypeptide.SELECTED DRAWING: NoneCOPYRIGHT: (C)2017,JPO&INPIT【課題】ＦｃγＲに対する結合を最適化した、Ｆｃ領域のより優れた機能改変方法の提供。【解決手段】アミノ酸配列の異なる２つのポリペプチド（第一のポリペプチド及び第二のポリペプチド）から成るＦｃ領域を有するヘテロ二量化ポリペプチドを作製することにより、該Ｆｃ領域が第一のポリペプチドのみからなるホモ二量化体又は第二のポリペプチドから成るホモ二量化体と比べて、Ｆｃ領域の機能が改善されたＦｃ領域を含むヘテロ二量化ポリペプチド。【選択図】なし
