IL-17 secreting γδT cells, CD4+ T cells, and CD8+ T cells may infiltrate the parenchyma within hours after stroke onset, peak by day 3, and aggravate ischemic injury [68,103,104], as do natural killer T cells [105], while regulatory lymphocytes (Tregs) expressing the forkhead box P3 (Foxp3) transcription factor [106,107] have traditionally been regarded as exhibiting neuroprotective activity [108,109]. The gene discussed is FOXP3; the disease is Stroke.