β-arrestin is a type of regulatory protein, including two main family members: β-arrestin1 and β-arrestin2. They are composed of multiple functional domains and are able to interact with G protein-coupled receptors (GPCRs). β-arrestin is located in multiple locations within cells, participating in the desensitization and internalization of GPCRs, and activating non-G protein-dependent signaling pathways, such as MAPK and PI3K/Akt. Mutations or dysregulated expression of these proteins are associated with a variety of diseases, including cardiovascular disease, neurodegenerative diseases, and cancer.