Zabini D et al. found a significant dysregulation of circulating inflammatory cytokines in both CTEPH and IPAH patients, showing increased expression of a broad range of inflammatory factors, such as IL-6, IL-8, IL-10, y-interferon-induced protein 10 (IP-10), monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-9 [49]. Here, CCL2 is linked to chronic thromboembolic pulmonary hypertension.