IFNG and neoplasm: Neuropilin‐1 (Nrp1), a trans‐membrane molecule, is needed to maintain the stability and function of tumor‐infiltrating Tregs but is dispensable for peripheral Tregs.30 Overacre‐Delgoffe et al30 recently found that a high frequency of Nrp1−/− Tregs in the tumors produce IFNγ, which suppress surrounding WT Tregs in the tumor and in turn facilitated tumor elimination.