AMBP (alpha-1-microglobulin/bikunin precursor) is a hepatically-synthesized protein that generates two functionally distinct products through proteolytic cleavage: alpha-1-microglobulin and bikunin 1. Bikunin functions as a Kunitz-type serine protease inhibitor with high catalytic efficiency for Factor Xa, potentially acting as an anticoagulant by inhibiting prothrombin activation, and also inhibits trypsin, chymase, and tryptase 2. Alpha-1-microglobulin, a lipocalin with immunosuppressive properties, is distributed at body-environment interfaces including lungs, intestine, kidneys, and placenta, consistent with anti-inflammatory and protective roles 2. AMBP expression is tightly controlled by hepatocyte-enriched nuclear factors 1. Recent studies demonstrate protective functions in cardiovascular disease: AMBP overexpression significantly reduced aortic valve calcification by inhibiting ERK1/2 and JNK phosphorylation through competitive binding to FHL3, preventing osteogenic differentiation of valvular interstitial cells 3. AMBP polymorphisms show associations with atherothrombotic stroke risk in Han Chinese populations, particularly through gene-environment interactions with hypertension 4. Plasma AMBP levels differentiate heart failure with preserved ejection fraction and pulmonary hypertension from pulmonary arterial hypertension, with potential diagnostic utility 5. These findings suggest AMBP as a therapeutic target for cardiovascular disease prevention.