SUCNR1 encodes a G protein-coupled receptor that binds succinate and mediates diverse physiological processes through Gq/GNAQ or Gi/GNAI signaling pathways 1. The receptor serves as a critical metabolic sensor linking cellular stress, inflammation, and energy homeostasis. In macrophages, SUCNR1 exhibits context-dependent immune regulation, promoting anti-inflammatory M2 polarization through Gq signaling under normal conditions 12, while facilitating pro-inflammatory responses in activated M1 macrophages. The receptor plays important roles in cancer progression, where tumor-derived succinate activates SUCNR1 to promote macrophage polarization into tumor-associated macrophages and enhance metastasis via PI3K-HIF-1α signaling 3. In adipose tissue, SUCNR1 controls energy metabolism by regulating leptin expression through AMPK-JNK-CEBPA and circadian clock pathways 4. During exercise, muscle cells release succinate in a pH-dependent manner, which activates SUCNR1 in non-muscle cells to coordinate tissue remodeling, innervation, and strength adaptation 5. SUCNR1 also contributes to liver inflammation regulation, where elevated succinate levels can drive pathological responses in stellate cells and macrophages 6. Additionally, the receptor supports CD8+ T cell cytotoxicity through autocrine succinate signaling 7.