LTB4R2 (leukotriene B4 receptor 2) is a low-affinity G protein-coupled receptor that binds leukotriene B4 and mediates immune cell chemotaxis through phosphatidylinositol-calcium signaling pathways. The receptor demonstrates ligand specificity with the rank order LTB4 > 12-epi-LTB4 > LTB5 > LTB3 and is involved in granulocyte and macrophage migration 1. Recent studies reveal significant pathological roles beyond inflammation. In triple-negative breast cancer, LTB4R2 promoter hypomethylation leads to gene upregulation and correlates with poor patient survival, suggesting its potential as a therapeutic target 2. The LTB4-LTB4R2 axis promotes cancer stemness in intrahepatic cholangiocarcinoma, where cancer-associated fibroblasts educate myeloid-derived suppressor cells to enhance tumor aggressiveness through 5-lipoxygenase-mediated LTB4 production 3. Similarly, in ovarian cancer, the ALOX5/LTB4/LTB4R2 pathway activates PI3K/AKT signaling to promote epithelial-to-mesenchymal transition and metastasis 4. LTB4R2 expression is elevated in rheumatoid arthritis-associated interstitial lung disease, indicating involvement in fibrotic processes 5. CRISPR screening identifies LTB4R2 as a druggable vulnerability in lung cancer, highlighting its therapeutic potential across multiple malignancies 6.