Increased levels of FOXP3+ Tregs in the peripheral blood and tumor tissue have been reported in patients with various types of cancer, including ovarian [9,10], breast [11], hepatocellular carcinoma [12] and other tumors [13]; the accumulation of Tregs in local lymph nodes or in tumors is associated with a less favorable prognosis [9-14]. This evidence concerns the gene FOXP3 and cancer.