Recombinant Anti-CD28 x Anti-EPCAM 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-CD28/EPCAM tandem scFv is fused to the Fc domain. The engineered fragment format is used to extend the half-life. This BsAb can retarget T cells to tumor cells. It is designed for the research of Melanoma; Glioblastoma multiforme (GBM); Non-small cell lung (NSCLC); Colorectal cancer (CRC); Solid tumors therapy.