ADGRE1 (formerly known as EMR1 or F4/80) is an adhesion G protein-coupled receptor that functions as a macrophage marker and regulator of immune cell adhesion 1. The receptor is widely used as a marker for identifying macrophages in various tissues, including the kidney, liver, heart, and reproductive organs 2345. ADGRE1+ macrophages play crucial roles in inflammatory responses across multiple organ systems. In acute kidney injury, increased infiltration of ADGRE1+ macrophages is associated with more severe tissue damage and inflammation 2. Similarly, ADGRE1+ macrophages accumulate in the septic heart and contribute to cardiac dysfunction 4. In reproductive biology, ADGRE1+ decidual macrophages are essential for normal pregnancy, with their proper residence and retention being critical for maternal-fetal immune tolerance 5. The receptor appears to be involved in macrophage adhesion, tissue infiltration, and inflammatory responses, making it an important marker for studying macrophage-mediated pathological processes. However, the specific signaling mechanisms and direct functional consequences of ADGRE1 activation remain incompletely characterized in the provided literature.