Rev-ErbA is a member of the nuclear receptor family, primarily consisting of two isoforms: Rev-ErbAα and Rev-ErbAβ. These proteins are expressed in various tissues, especially in the liver, brain, muscles, and adipose tissue. They regulate gene expression by binding to specific sequences on genes, playing a crucial role in controlling circadian rhythms, lipid and glucose metabolism. The activity of Rev-ErbA is regulated by circadian rhythms, and abnormalities in its expression level and gene mutations are associated with various diseases, such as metabolic syndrome, cardiovascular diseases, and sleep disorders.