Interconnected with the complement system in cluster n.1 is antithrombin III (ANT3 codified by the SERPINC1 gene), which, in addition to its known anticoagulant activity, exhibits anti-inflammatory properties, showing a slight increase in urinary levels in the acute phase of glomerulonephritis, but a large increase during the relapse phase of nephrotic syndrome, as reviewed in [40]. The gene discussed is SERPINC1; the disease is glomerulonephritis.