Recombinant Anti-CD28 x Anti-EPCAM 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 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.