SOCS1 and systemic lupus erythematosus: Although it was occasionally reported that the SOCS1 mRNA level increases in peripheral blood mononuclear cells of patients with SLE (18, 19), many more studies revealed significant downregulation of SOCS1 expression in these cells (20–22), and steroid administration to these cells upregulates SOCS1 expression in a dose- and time-dependent manner (22).