Tregs are crucial for physiological immune homeostasis and their absence leads to severe autoimmunity, which is universally fatal in ‘scurfy’ mice that lack Foxp3 expression [45] and manifests as a life-limiting multisystem disorder in humans – the immune dysregulation, polyendocrinopathy, enteropathy, X-linked syndrome (IPEX) [46], [47]. Here, FOXP3 is linked to Autoimmunity.