There is disclosed compositions and methods relating to or derived from anti-CD137 antibodies. More specifically, there is disclosed fully human antibodies that bind CD137, CD137-antibody binding fragments and derivatives of such antibodies, and CD137-binding polypeptides comprising such fragments. Further still, there is disclosed nucleic acids encoding such antibodies, antibody fragments and derivatives and polypeptides, cells comprising such polynucleotides, methods of making such antibodies, antibody fragments and derivatives and polypeptides, and methods of using such antibodies, antibody fragments and derivatives and polypeptides, including methods of treating a disease requiring either stimulation of immune responses or suppression. Diseases amenable to treatment is selected from the group consisting of cancers, autoimmune diseases and viral infections.