Further, in a murine model of PH-LHD, it has been suggested that IL-6 signaling pathway is activated [19] and elevated IL-6 levels have also been shown to correlate with lower quality of life, worse right ventricular function and stroke volume in patients with pulmonary arterial hypertension (group 1 PH) [20]. Here, IL6 is linked to pulmonary arterial hypertension.