Disclosed are fusion proteins comprising a biologically active molecule and an immunoglobulin (Ig) Fc domain which is linked to the biologically active molecule. The Fc domain is a hybrid human Fc domain of (i) IgG1, IgG2 or IgG4 or (ii) IgG4 and IgD. The hybrid Fc is useful as a carrier of biologically active molecules.本發明揭示包括生物活性分子及連接於該生物活性分子的免疫球蛋白(Ig)Fc結構域的融合蛋白質。該Fc結構域為(i)IgG1、IgG2或IgG4或(ii)IgG4及IgD之雜合人類Fc結構域。該雜合Fc適用作為生物活性分子的載體。由於本案的圖僅為說明用,並非本案的代表圖。故本案無指定代表圖。