There were 6 idiopathic, 2 hereditary PAH, and 2 PAH associated with connective tissue disease (no scleroderma), who were treated by endothelin receptor antagonist (ERA) in 9, phosphadiesterase-5 (PDE-5) inhibitor in 5, soluble guanylate cyclase (sGC) stimulator in 4, prostacyclin (IP) receptor agonist in 6, oral prostacyclin in 2, and intravenous prostacyclin analogue (PGI2) in 5 (Table 1). Here, PDE5A is linked to scleroderma.