CCL5 and cancer: The CD4/CD8 of patients in the lymph node positive group increased significantly, and this result was more obvious in tumor tissue (14 fold) than that in peripheral blood, indicating that the main environment for CD4+ cells promoting cancer progression was in tumor tissue rather than peripheral blood, therefore, we speculate that tumor tissue may be the main source of CCL5; in other words, a considerable proportion of CCL5 in serum is produced by tumor tissue and released locally and throughout the whole body, which then affects the development of tumors in the whole body.