ACKR1 and cancer: PDPN+ cancer-associated fibroblasts enhance GC angiogenesis via the CCL2-ACKR1 axis (329)Ephrin A1 Stimulates CCL2 Secretion to Facilitate Pre-metastatic Niche Formation and Promote GC Liver Metastasis (330)CCL2 expression correlates closely with HIF-1α expression in GC (331)