The GCC2 protein, fully named GRIP and Coiled-Coil Domain-Containing Protein 2, is a key adaptor protein in the intracellular Golgi-endosomal membrane transport system. It specifically anchors to the Golgi membrane via its GRIP domain and is primarily responsible for mediating retrograde vesicular transport from endosomes to the Golgi apparatus, participating in the recycling and sorting of various cargo proteins, such as the mannose-6-phosphate receptor. Recent studies have revealed that GCC2 regulates the subcellular localization of the GATOR complex, thereby acting as an important upstream regulator of the mTORC1 signaling pathway, which influences cell growth, metabolism, and autophagy. Dysfunction of GCC2 is closely associated with neurodevelopmental disorders and tumorigenesis, underscoring its significance in cell biology and disease research.