United Therapeutics is a biotechnology company. Co. markets and sells four commercial therapies to treat pulmonary arterial hypertension (PAH): Remodulin® (treprostinil) Injection; Tyvaso® (treprostinil) Inhalation Solution; Orenitram® (treprostinil) Extended-Release Tablets; and Adcirca® (tadalafil) Tablets. Co. also markets and sells an oncology product, Unituxin® (dinutuximab) Injection for treatment of high-risk neuroblastoma. Co. also engages in research and development of new indications and formulations and delivery devices for its existing products, as well as new products to treat PAH and other conditions. Co. also engages in organ transplantation-related technologies.