A fusion protein comprises a nanocage monomer； and an antibody or fragmentthereof linked to the nanocage monomer,the antibody or fragment thereof comprising a first member of a binding pair；wherein a plurality of the fusion proteins self-assembleto form a nanocage in which a plurality of the antibodies or fragments thereofdecorate the exterior surface of the nanocage, wherebythe first member of the binding pair is exposed for interacting with a secondmember of a binding pair.
