CCL17 and esophageal squamous cell carcinoma: We found that CCL17/TARC stimulated proliferation of MCC13 cells, whereas several studies have reported that CCL17/TARC or CCL22-associated CD4+CD25+Foxp3+ increases the population in tumor-infiltrating lymphocytes (TILs), with peripheral blood lymphocytes (PBLs) being one of the reasons for impaired anti-tumor immunity in both gastric and esophageal squamous cell carcinoma [44, 45].