Kininogen-1 (KNG1) is also known as high molecular weight kininogen, Alpha-2-thiol proteinase inhibitor, Fitzgerald factor, Williams-Fitzgerald-Flaujeac factor, which can be cleaved into the following 6 chains:Kininogen-1 heavy chain, T-kinin, Bradykinin, Lysyl-bradykinin, Kininogen-1 light chain, Low molecular weight growth-promoting factor. Kininogen-1 is a secreted protein which contains three cystatin domains. HMW-kininogen plays an important role in blood coagulation by helping to position optimally prekallikrein and factor XI next to factor XII. As with many other coagulation proteins, the protein was initially named after the patients in whom deficiency was first observed.Patients with HWMK deficiency do not have a hemorrhagic tendency, but they exhibit abnormal surface-mediated activation of fibrinolysis.