On the one hand, FOXP3 expression has been reported to be widespread in the normal epithelium and tissue of the breast, prostate, ovary and brain, and down-regulated in matched tumor cells [2, 4, 19, 26], although in mice, the level of Foxp3 mRNA expression in these tissues was shown to be approximately 100-fold lower than that in Treg cells [27]. This evidence concerns the gene FOXP3 and neoplasm.