Increased MCP-1 levels are associated with animal models of pulmonary hypertension and the human PH subgroup chronic thromboembolic pulmonary hypertension (Group 4—CTEPH) Specifically, MCP-1 induces vascular remodeling by promoting inflammation and cell migration in chronic thromboemboli [32]. This evidence concerns the gene CCL2 and chronic thromboembolic pulmonary hypertension.