AOC3 and arthritic joint disease: Concentrations of VAP-1 in hepatic tissue, and soluble (s)VAP-1 in serum, are elevated in chronic liver diseases and correlate with histological fibrosis.11,12 Moreover, in vivo data demonstrate that blocking VAP-1 function with an anti-mouse VAP-1 antibody significantly alleviates inflammation in mouse models of arthritis and lung inflammation.