Avihingsanon et al. detected urinary CXCL10 and CXCR3 mRNA levels in 26 patients, 14 of whom had class IV nephritis, and found that elevated urinary CXCL10 and CXCR3 levels could distinguish class IV LN from others with an accuracy greater than the current available clinical markers, namely, the SLE disease activity index (SLEDAI), proteinuria, renal function, or urinalysis. The gene discussed is CXCL10; the disease is nephritis.