KNG1 (High-molecular-weight kininogen, HMWK) is a circulating plasma polypeptide that plays an important role in blood coagulation by helping to optimally position prekallikrein and factor XI next to factor XII. It inhibits the thrombin- and plasmin-induced aggregation of thrombocytes. Furthermore, KNG1 peptides functions in smooth muscle contraction, the induction of hypotension, natriuresis and diuresis, regulation of blood glucose level, and regulation of inflammation and vascular permeability. In immunohistochemistry of normal tissue, it is specifically positive in plasma and has extracellular and cytoplasmic positivity in the kidney. References: The UniProt Consortium. Nucleic Acids Res. 47: D506-515 (2019); Nucleic Acids Res. 2016 Jan 4;44(D1):D733-45, PMID:26553804