NCOA2 is a transcriptional coactivator that regulates steroid and nuclear receptor signaling, functioning primarily through the steroid-binding domain (AF-2) of target receptors 12. It plays critical roles in metabolic homeostasis by controlling energy balance between white and brown adipose tissues and regulating glucose metabolism through modulation of G6PC1 expression via RORA coactivation 3. NCOA2 is clinically significant as an oncogene, identified in approximately 11% of prostate cancers through copy-number amplification 4. Beyond prostate cancer, NCOA2 participates in pathogenic fusion events in pediatric sarcomas: VGLL2-NCOA2 fusions drive infantile rhabdomyosarcoma by reactivating developmental programs including ARF6 expression 5, while HEY1-NCOA2 and NSD3::NCOA2 fusions are associated with mesenchymal chondrosarcoma and head and neck carcinomas respectively 67. Additionally, NCOA2 genetic polymorphisms show associations with obesity susceptibility and dyslipidemia in population studies 8. These findings establish NCOA2 as a dual-function protein: essential for normal metabolic regulation but pathogenic when dysregulated through amplification or fusion in malignancies.