PTGER3 (prostaglandin E receptor 3) is a seven-transmembrane G protein-coupled receptor that mediates cellular responses to prostaglandin E2 (PGE2). The receptor couples to both inhibition of adenylate cyclase via Gi proteins and elevation of intracellular calcium 1. PTGER3 contains multiple isoforms generated through alternative splicing of its C-terminal regions 1. PTGER3 serves critical physiological functions including fever generation in response to pyrogens and regulation of platelet aggregation and hemostasis. Recent evidence reveals that peripheral sensory neurons expressing PTGER3 detect locally produced PGE2 in the nasopharynx and relay signals to the brainstem to orchestrate systemic sickness responses during respiratory viral infections 2. Disease relevance spans multiple conditions. Genetic variations in PTGER3 associate with asthma susceptibility and severity in Korean populations 3. PTGER3 expression is dysregulated across cancers: reduced expression correlates with poor prognosis in renal carcinoma and triple-negative breast cancer 45, while elevated expression promotes ovarian cancer growth and chemoresistance through Ras-MAPK/Erk signaling 6. In diabetic nephropathy, downregulated PTGER3 participates in competing endogenous RNA networks associated with renal injury 7. PTGER3 also emerges as a biomarker in endometriosis with therapeutic drug targets identified 8. These findings position PTGER3 as a multifunctional regulator with therapeutic potential across inflammatory, infectious, and malignant diseases.