CD63 and soft tissue sarcoma: Comparing all soft tissue sarcoma patients with a positive history of VTE (n = 11) to all soft tissue sarcoma patients without a history of VTE (n = 28), we found significantly higher levels of activated platelet-derived (CD62P- and CD63-positive) microvesicles (p = 0.0078 and p = 0.0450, respectively; Fig. 3).