They measured serum MBL levels in 749 patients with IgA glomerulonephritis and 489 healthy controls and found that the symptoms of hematuria and infection were significantly higher in patients with low MBL levels (<100 ng/mL) than in those with sufficient (100-3540 ng/mL) MBL levels. The gene discussed is MBL2; the disease is IgA glomerulonephritis.