Animal studies indicate that mild hyperbilirubinemia prevents atherosclerosis progression by improving lipid profiles and modulating the mRNA expression of vascular cell adhesion molecule 1 (VCAM-1), ICAM-1, inducible nitric oxide synthase (iNOS), and lectin-like LDL receptor 1 (LOX-1) (42). This evidence concerns the gene NOS2 and atherosclerosis.