CD4 and neoplasm: T cells are normally a major component of tumor-infiltrating immune cells.3 Recently, a subset of regulatory T cells (Tregs) with potent immunosuppressive properties has been detected in human GC, and increased such Tregs was also associated with poor prognosis of GC patients.4 Although most data on circulating5 or tumor-infiltrating6 Tregs belonged to CD4+CD25+Foxp3+ T cells, little is known about the phenotype, regulation, function, and clinical relevance of Treg subsets in human gastric tumors.