Clinical improvement and multimodal regulatory effects of Hsp90 inhibition on, e.g., cell signaling, proinflammatory cytokine secretion, dsDNA antibodies, proteinuria, or lymphocytes activity (e.g., expansion of Treg or reduction in pathogenic T and B cell lineage populations) in SLE was revealed using experimental animal models. The gene discussed is HSP90AA1; the disease is systemic lupus erythematosus.