1. Diantibody molecule containing the first polypeptide chain and the second polypeptide chain, where the first polypeptide chain contains (i) a first domain containing the binding region of the variable domain of the light chain of the first immunoglobulin (VL1) specific for the first epitope, (ii) a second domain containing the binding region of the heavy chain variable domain of the second immunoglobulin (VH2) specific for the second epitope, and (iii) a third domain containing the Fc domain or part thereof, the first domain and the second domain being covalently linked so that the first domain and the second domain was not associated with the formation of an epitope binding site； where the second polypeptide chain contains (i) a fourth domain containing the binding region of the light chain variable domain of the second immunoglobulin (VL2), (ii) a fifth domain containing the binding region of the heavy chain variable domain of the first immunoglobulin (VH1), and (iii) a sixth domain containing an Fc domain, the fourth domain and the fifth domain being covalently linked such that the fourth domain and the fifth domain do not associate with the formation of the epitope binding site； where the th domain and the fifth domain are associated with the formation of the first binding site (VL1) (VH1), which binds the first epitope； where the second domain and the fourth domain are associated with the formation of the second binding site (VL1) (VH2), which binds the second epitope； and where: (1) said second and said third domains； or (2) said fifth and said sixth domains； linked to each other using an integrated polypeptide linker having a sequence selected from the group consisting of SEQ ID NO: 278-298.2. Diantibody molecule according to claim 1, where the third domain of the complementary1. Молекула диантитела, содержащая первую полипептидную цепь и вторую полипептидную цепь,где первая полипептидная цепь содержит (i) первый домен, содержащий связывающую область вариа
