CXCR4 and cancer: A recent study showed that C-C motif chemokine receptor type 2 (CCR2)-recruited monocytes differentiate into migratory TAMs that assist with cancer cell motility through the extracellular matrix before differentiating into perivascular macrophages via C-X-C motif chemokine receptor 4 (CXCR4)/CXCL12 signaling (78).