VWF and neoplasm: For example, 1) thrombin is one of the most important platelet activators, and the local concentration of thrombin in the bronchoalveolar lavage fluid of 15 OS patients with lung metastasis increased up to more than 100-fold compared with patients without lung metastasis [34]; 2) von Willebrand factor (vWF) is also involved in platelet aggregation and processes critical to hematogenous tumor cell metastasis to the lung, and it was shown that vWF is expressed at higher levels in metastases than in primary tumors [35].