Recombinant Anti-CEA x Anti-TNFα Bispecific Antibody (Bi-nanobody) is designed to be expressed as a VHH from anti-CEA antibody variable domains fused with a VHH from an anti-TNFα antibody variable domains. It contains a His-tag at the C/N terminus for affinity purification. The BsAb exits as monomer in reducing and non-reducing conditions. This BsAb can retarget cytokine (TNFα) to tumor cells. It is designed for the research of Breast cancer; Ovary cancer; Colon cancer; Lung cancer therapy.