Recombinant Anti-CD3 x Anti-CD38 Bispecific Antibody (F(ab')2-scFv2) is designed to be expressed as two chains combined via a hinge region. The scFv of the anti-CD3 specificity is fused to the C terminus of the anti-CD38 Fab fragment, or vice versa. This format comprises four binding sites (two same scFv regions and two same Fab fragments), two for each antigen. This BsAb can block two receptors simultaneously. It is designed for the research of Multiple myeloma (MM) therapy.