Patients with CS present higher levels of: FII, FV, FVIII, FIX, FXI, FXII, FVIII, and von Willebrand factor (vWF), as well as increased levels of fibrinolytic inhibitors, e.g., plasminogen activator inhibitor type 1 [1–4, 23]. This evidence concerns the gene VWF and Cowden syndrome 1.