ERR (Estrogen Related Receptors) is part of the nuclear receptor superfamily, comprising three main subtypes: ERRα, ERRβ, and ERRγ. These receptors influence various metabolic processes by regulating gene expression, despite not binding estrogen directly. ERR is widely distributed in tissues such as the heart, muscles, bones, and brain, where it participates in energy metabolism, cardiac function, and skeletal maintenance. Specific expression and function of ERR genes are significant through tissue-specific expression and the regulation of various biological processes. Additionally, mutations or dysregulation in ERR genes are associated with the onset and progression of various diseases, including cardiovascular disorders, metabolic dysfunctions, and cancer.