PAQR5 is a plasma membrane progesterone receptor coupled to G proteins that mediates non-genomic progesterone signaling through Gi-mediated pathways 1. The receptor may play roles in oocyte maturation and reproductive processes 12. In cancer biology, PAQR5 exhibits context-dependent functions. In hepatocellular carcinoma, PAQR5 is significantly upregulated and drives malignant progression by activating NF-κB signaling through ERK phosphorylation, promoting proliferation, invasion, epithelial-mesenchymal transition, and immune escape 3. Conversely, in clear cell renal cell carcinoma (ccRCC), PAQR5 expression is downregulated and functions as a tumor suppressor, inhibiting growth and metastasis by suppressing JAK/STAT3 signaling 4. Low PAQR5 expression in ccRCC correlates with poor survival outcomes and is negatively regulated by TGFβ1 5. Beyond cancer, PAQR5 shows reduced expression across multiple osteoarthritis-affected tissues (meniscus, cartilage, synovium) and is implicated in inflammatory and cholesterol metabolism processes during joint degeneration 6. In Crohn's disease, PAQR5 serves as a diagnostic and prognostic biomarker with immune regulatory significance 7. These findings suggest PAQR5 functions as a context-dependent regulator of cellular signaling with diverse pathophysiological roles.