The expression of FOXP3 and its role in human cancers.

FOXP3 is a transcription factor, which belongs to the family of FOX protein. FOXP3 was initially discovered in regulatory T cells and supposed to play a significant role in the process of regulatory T cell differentiation. Increasing evidence has shown that FOXP3 is also expressed in tumor cells. However, the results of tumor FOXP3 is inconsistent and even the opposite. In some types of human cancers, the expression of FOXP3 is upregulated, and it can promote the development of cancers, leading to a poor prognosis. While in some other types of cancers, it is a different story. The reason for the contradictory data is unknown. The discovery of FOXP3 isoforms, interaction between tumor cells and lymphocytes in the tumor microenvironment, subcellular location, and mutation of FOXP3 may provide some clues. In this review, we first summarize and analyze the recent development. The final section focuses on the regulation of FOXP3 expression.