Macrovascular evidence suggests that circ-SIRT1, derived from the circularization of exons 2 and 7 of the SIRT1 gene, is crucial to inflammation, hypertension, and atherosclerosis, and is significantly downregulated during aging, neointima formation, VSMC injury, pulmonary arterial hypertension, and angiotensin-II treatment [192,193,194,195]. The gene discussed is SIRT1; the disease is pulmonary arterial hypertension.