CXCL6 and metastatic malignant neoplasm in the lymph nodes: Comparative analysis of the CXC chemokine/receptor genes revealed significantly higher expression levels of genes encoding ELR+ CXC chemokines/receptors (CXCL1, CXCL3, CXCL6, CXCR1, and CXCR2) in bone metastases relative to lymph node metastases.