Moreover, peripheral recirculating immune cells between healthy controls and KCNK3 hereditary PAH patients show significant differences, including a relative reduction in naïve CD8+ and CD4+ T cells and naïve B cells, and reciprocal increases in memory CD8+ and CD4+ T cells and double negative CD4−/CD8− T cells. The gene discussed is KCNK3; the disease is pulmonary arterial hypertension.