IL1R2 and systemic lupus erythematosus: Together, common characteristics of lupus appear to be upregulation of members of the IL-1 family such as IL-1α and IL-1β and IL1R2, of the TNF/death receptor family such as TNF receptor II (TNFRSF1B), TRAIL (TNFSF10), and its decoy receptors, and a gene signature of IFN-α/β-regulated genes.