Research indicates that tumor tissues expressed ligands for these receptors of chemokines, with the interactions of CXCL12‐CXCR4, CXCL10‐CXCR3, and CCL19 –CCR7 play crucial role in attracting CD8+ T cells to infiltrate tumors.36, 37, 38, 39. This evidence concerns the gene CCR7 and neoplasm.