Recombinant Anti-CD55 x Anti-HLA-A Bispecific Antibody (Tandem scFv-Fc) is designed to be expressed as a homodimer, which has 2+2 antigen-binding valency. This format consists of one Fc region and two tandem scFv fragments, in which the anti-CD55/HLA-A tandem scFv is fused to the Fc domain. The engineered fragment format is used to extend the half-life. This BsAb can recruit complements to tumor cells. It is designed for the research of Renal cell cancer (RCC); Solid tumors therapy.