FOXP3 and neoplasm: In this early response, IFNγ is thought to slow tumor growth and improve CD8+ T cell-directed responses via enhanced antigen presentation.11 IFNγ can also drive regulatory T cell (Treg) fragility in which Foxp3+ Tregs become less suppressive and can secrete IFNγ themselves, allowing for better antitumor responses.12 Additionally, IFNγ can act on the tumor stromal cells, inducing regression of the vasculature supporting tumors, ultimately causing tumor shrinkage.13,14 However, the long-term role of IFNγ in immune equilibrium is unclear.