TNFRSF9 and systemic lupus erythematosus: In an attempt to understand whether agonistic anti-CD137 antibody could delay the onset of SLE development, 8-week old NZB x NZW F1 mice were treated with one i.p. injection of agonistic anti-CD137 antibody prior to the development of SLE phenotype and the appearance of serum anti-dsDNA antibodies.