CXCR4 and breast cancer: Analysis of the protein connectivity showed that the formyl peptide receptor 2 (FPR2), CXC motif chemokine receptor 4 (CXCR4), serum amyloid A 1 (SAA1), C-C motif chemokine receptor 5 (CCR5), formyl peptide receptor 1 (FPR1), C-C motif chemokine receptor 3 (CCR3), C-X3-C Motif Chemokine Ligand 1 (CX3CL1), C-X-C Motif Chemokine Ligand 11(CXCL11), G Protein-Coupled Receptor 37 (GPR37), Gamma-Aminobutyric Acid Type B Receptor Subunit 2 (GABBR2) and phospholipase C beta 1 (PLCB1) were hub nodes with degrees of ≥15 in breast cancer LM2 cell line (Table 1B).