Models with linear and quadratic terms described non-monotonic association between PAH-DNA adducts and anti-CD3/anti-CD28 (Fig 2A), while the models with 3rd -order polynomials described the associations between PAH-DNA adducts and IFNg, IL-1b, IL-2, IL-6, IL-10 and IL-17A. This evidence concerns the gene CD28 and pulmonary arterial hypertension.