Recombinant Anti-albumin x Anti-IL-6R Bispecific Antibody (Tandem Fab) is designed to be expressed as three chains derived from the variable domains of anti-albumin and anti-IL-6R parental antibodies. It contains a His-tag for affinity purification. And the two Fd regions are connected by a flexible linker. This BsAb can act as PK-modulated receptor antagonist. It is designed for the research of Lupus, rheumatoid arthritis therapy.