CD80 and osteosarcoma: It was demonstrated by Nagamore et al. that extrinsic (anti-CTLA-4 mAb) and intrinsic (lack of IgC-like domain in B7-1a) manipulations of the interactions of B7/CTLA-4 enhance the therapeutic efficiency of osteosarcoma vaccines that are based on B7, synergistically (Nagamori et al., 2002[42]).