RAP2C is a small GTP-binding protein belonging to the Ras/Rap family of GTPases, mapped to chromosome X.2 1. It cycles between GDP-bound inactive and GTP-bound active states, functioning as a molecular switch that regulates multiple cellular processes. Primary functions include SRE-mediated gene transcription activation 1, regulation of fibroblast activation through EPAC1/2-RAP2C-MAP4K7 signaling cascades 2, and modulation of mitochondrial dynamics by promoting RAP2C-DRP1 association to enhance oxidative phosphorylation 3. RAP2C is broadly expressed in liver, skeletal muscle, prostate, and other tissues 1. In cancer biology, RAP2C overexpression promotes osteosarcoma cell migration and invasion through increased MMP2 activity and Akt pathway activation, independent of effects on proliferation or apoptosis 4. In neuroprotection, RAP2C expression is downregulated during spinal cord ischemia-reperfusion injury via miR-204 targeting, and RAP2C restoration reduces hypoxia-induced neuronal apoptosis 5. Clinically, genome-wide association studies identified RAP2C variants as associated with gestational duration and postpartum hemorrhage risk, suggesting involvement in reproductive biology through progesterone signaling dysregulation 67. These findings position RAP2C as a therapeutic target in fibrosis, cancer metastasis, and obstetric complications.