Recombinant Anti-CD55 x Anti-HLA-A Bispecific Antibody (Diabody) is designed to be expressed as two polypeptide chains respectively. The two chains are cross-over pairing to form a dimer. It contains a His-tag for affinity purification. This BsAb can recruit complements to tumor cells. It is designed for the research of Renal cell cancer (RCC); Solid tumors therapy.