Helios expression in FoxP3(+) T regulatory cells.

Recent work debates the suitability of Helios, an Ikarios family transcription factor, as a marker of thymic-derived natural T regulatory cells. However, Helios expression could be of particular importance in cancer. We and others reported that the majority of peripheral and tumour-infiltrating FoxP3(+) Tregs expresses Helios. Additionally, recent observations indicate that FoxP3(+)Helios(+) Tregs possess more suppressive characteristics, as compared to FoxP3(+)Helios(-) Tregs.