NOS3 and atherosclerosis: Functionally, atherosclerosis-linked circRNAs converge on several core pathways: (i) endothelial nitric oxide synthase (eNOS) regulation and barrier function, (ii) smooth muscle cell contractile-to-synthetic phenotype transitions, (iii) macrophage M1/M2 polarization and foam cell formation, and (iv) extracellular matrix remodeling and plaque stability [46].