Antibodies and fragments that bind to the protein target Dickkopf (DKK1) are provided, as are methods of use and kits, for treating a target cell, in particular, a cell associated with an osteolytic condition.本發明提供可結合蛋白目標Dickkopf(DKK1)之抗體及片段,亦提供使用方法及套組,以治療目標細胞,特別係與溶骨性病況相關之細胞。