Naïve T cells express CD45RA and are usually functionally quiescent6; but in responses to stimuli, they may produce a high level of chemokines, such as CXCL8, which mediates neutrophil migration to a tumor and promotes tumor growth.7 In contrast, memory T cells are of the CD45RO+ phenotype,8 and secrete IFN‐γ, CCL4, XCL1 and other cytokines to kill tumor cells directly or indirectly.9, 10. This evidence concerns the gene XCL1 and neoplasm.