GPRC5A is an orphan G protein-coupled receptor that functions as a context-dependent regulator of cellular homeostasis and tumor progression. The receptor serves as a parathyroid hormone-inducible gene that negatively regulates osteoblast proliferation and differentiation by interacting with BMPR1A and suppressing BMP signaling 1. GPRC5A exhibits tissue-specific and cancer-type-dependent expression patterns, functioning as a tumor suppressor in lung cancer while promoting metastasis in other malignancies 23. In triple-negative breast cancer, GPRC5A promotes liver metastasis and docetaxel resistance by preventing LAMTOR1 degradation and activating mTORC1/p70s6k signaling 4. The receptor facilitates lung colonization in esophageal squamous cell carcinoma through a GPRC5A/WWP1/LATS1/YAP1 pathway that promotes early disseminated cancer cell implantation 5. GPRC5A expression is regulated by m6A methylation via METTL3/YTHDF1 and serves as a potential biomarker for gastric cancer diagnosis 6. Meta-analysis demonstrates that higher GPRC5A expression correlates with worse overall survival and advanced tumor characteristics, though prognostic significance varies by cancer type 7. The receptor represents a promising therapeutic target for multiple pathological processes including cancer, inflammation, and metabolic disorders 3.