FOXP3 and cancer: Our data suggested that the TME might enhance the conversion of FoxP3−Helios+ Treg subset into FoxP3+Helios+ Treg subset as FoxP3−Helios+ subset constituted more than half of different FoxP3 and Helios expressing Treg subset in NT and peripheral blood of cancer patients, but within the TME, FoxP3−Helios+ comprised of around 30% of Treg population and FoxP3+Helios+ Treg subset increased significantly and constituted more than 54% of the population among the three Treg subsets.