PTGER1 (prostaglandin E receptor 1) is a G protein-coupled receptor that mediates cellular responses to prostaglandin E2 (PGE2) through Gq protein coupling and activation of phosphatidylinositol-calcium second messenger systems. PTGER1 plays protective roles in cardiac tissue by inhibiting ferroptosis through PKC/Nrf2 signaling activation, which upregulates antioxidative genes including GPX4 and SLC7A11 1. In ovarian granulosa-lutein cells, PTGER1 partially mediates PGE2-induced progesterone synthesis and 11β-hydroxysteroid dehydrogenase activity regulation 2. The receptor shows disease relevance across multiple contexts: it promotes cancer stemness in cholangiocarcinoma when activated by increased PGE2 levels 3, is overexpressed in EBV-negative gastric cancers as part of the COX-2/PGE2 inflammatory pathway 4, and serves as an autophagy-related biomarker in diabetic nephropathy 5. Copy number variations in PTGER1 are associated with NSAIDs-induced urticaria and angioedema, suggesting genetic susceptibility to arachidonic acid pathway dysregulation 6. Genomically, PTGER1 is linked to GIPC1 on chromosome 19.2-p13.1 7. These findings establish PTGER1 as a critical mediator of PGE2 signaling with both protective and pathological roles depending on tissue context and disease state.