Recombinant Anti-CD3 x Anti-CEA Bispecific Antibody (Tandem Fab) is designed to be expressed as three chains derived from the variable domains of anti-CD3 and anti-CEA parental antibodies. It contains a His-tag for affinity purification. And the two Fd regions are connected by a flexible linker. This BsAb can retarget T cells to tumor cells. It is designed for the research of Colorectal cancer (CRC); Breast cancer; Lung cancer; Gastric cancer therapy.