They found that the interaction between a chemokine and its corresponding chemokine receptor had a critical role in organ-specific cancer metastasis and they suggested that the CC-chemokine receptor 7 (CCR7) and CC-chemokine ligand 21/secondary lymphoid-tissue chemokine (CCL21/SLC) axis might be responsible for lymph node metastasis. This evidence concerns the gene CCR7 and cancer.