TBX21 and neoplasm: Classically, GATA3 binds directly to the ST2 promoter to increase ST2 expression through a positive feedback loop in Treg cells42,43 but in the context of a tumor, IFN-γ in Treg cells enhances tumor-killing immune responses44, and the transcription factor Tbet controls type 1 immune responses in a subset of Treg cells9,18.