Used in the treatment of pulmonary arterial hypertension (PAH) to delay disease progression and reduce the risk of hospitalization. It works by activating the prostacyclin pathway, which helps relax and widen blood vessels in the lungs, lowering pulmonary vascular resistance and improving exercise capacity. Often prescribed for long-term management in patients with WHO Group I PAH, it can be used alone or in combination with other PAH therapies such as endothelin receptor antagonists or phosphodiesterase-5 inhibitors.