TF and familial pancreatic carcinoma: Injection of TF-positive microvesicles isolated from a human pancreatic cell line increased venous thrombosis when injected into mice, while inhibition of TF prevented this effect.58 Several studies have described the presence of TF-positive microvesicles in the circulation of patients with solid cancers, with the highest levels of microvesicle-TF activity reported in patients with pancreatic cancer.