CXCL12 is a homeostatic chemokine that functions primarily through binding to receptors CXCR4 and CXCR7 to regulate cell migration and activation 1. In normal physiology, CXCL12 induces migration and activation of hematopoietic progenitor cells, endothelial cells, and leukocytes, playing essential roles in embryogenesis, hematopoiesis, and angiogenesis 1. The chemokine exhibits context-dependent activity: at lower concentrations it acts as a chemoattractant for lymphocytes, while higher concentrations may produce chemorepellent effects 2. CXCL12 can be regulated through interaction with cell surface proteoglycans and post-translational modifications that preserve local activity 3. In disease contexts, CXCL12-CXCR4/CXCR7 signaling promotes tumor cell proliferation, survival, angiogenesis, and metastasis across multiple cancer types including leukemia, breast cancer, lung cancer, and pancreatic cancer 4. Binding to CXCR4 activates pro-survival pathways including PI3K/mTOR and MEK/ERK, while CXCR7 engagement triggers β-arrestin signaling 2. The axis also contributes to fibrotic disease pathology through effects on inflammation, immunity, and epithelial-mesenchymal transition 5. Recent evidence indicates CXCL12 participates in androgenic alopecia, with androgen-induced CXCL12 expression in human hair follicle cells contributing to hair miniaturization 6. CXCL12-CXCR4/CXCR7 represents a promising biomarker and therapeutic target, with CXCR4 antagonists like Plerixafor currently in clinical trials 2.