Among tumor-infiltrating Tregs, investigators detected T-bet+Foxp3+CD4+ T cells with a higher expression of typical Treg factors, such as ICOS, GITR, CD103, CTLA4, PD-1, and IL-10 as compared to CD4+ T cells, which express either T-bet or Foxp3 [32]. The gene discussed is PDCD1; the disease is neoplasm.