CLINICAL IMPLICATIONS: TF expression was increased in the plasma of patients with CTEPH, partly due to an increase in monocyte TF mRNA levels. Monocyte TF plays a key role during the CTEPH thrombotic process. At the same time, the inflammatory factors CRP, TNF-α and MCP-1 increased in the plasma of patients with CTEPH and correlated with mPAP, indicating that they are involved in the pathogenesis of CTEPH and determine disease severity. Moreover, high expression of TF correlated with expression of the inflammatory factors CRP, TNF-α and MCP-1 in patients with CTEPH. TF, CRP, TNF-α, and MCP-1 may not be attractive molecules to test for screening of CTEPH but may have value in determination of prognosis, which was not evaluated in our study.