In the previous study, ELISA 1, multivariable logistic- and cox-regression analysis showed that CCL21, anti-centromenre antibody (ACA), systolic pulmonary artery pressure (sPAP) and diffusing capacity of carbon monoxide (DLCO) were significantly associated with PAH and predictive of PAH (15). The gene discussed is CCL21; the disease is pulmonary arterial hypertension.