Forkhead box p3 (Foxp3<sup>+</sup>) regulatory T cells (Tregs) are abundant in the tumor microenvironment where they dampen functions of host anti-tumor immunity and promote cancer progression.
Regulatory T cells (Tregs) are CD4+ T cells that express CD25 and transcription factor Forkhead box P3 (FOXP3), and Tregs play a central role in regulation of tumor immunity.
Regulatory T (Treg) cells expressing the transcription factor Foxp3 are critical for the prevention of autoimmunity and the suppression of anti-tumor immunity.
Therefore, it is crucial to investigate the "true Treg (eTreg)" population, rather than the entire FOXP3 population, with regards to their effect on tumor immunity.