By performing multivariable logistic- and cox-regression analysis in the ELISA 2 cohort, we found that CCL21 were borderline significantly associated with PAH and sPAP were significantly associated with PAH (OR 4.53 (95% CI 0.98-20.92), p=0.053 and OR 1.06 (95% CI 1.00-1.11), p=0.037, respectively) and predictive for PAH (HR 1.58 (95% CI 1.02-2.44), p=0.038 and HR=1.03 (95% CI 1.02-1.05), p<0.001, respectively), shown in Table 4. This evidence concerns the gene CCL21 and pulmonary arterial hypertension.