FOXP3 and autoimmune disease: Contrary to adults, Foxp3 degradation in neonates led to severe autoimmune disease featuring pronounced T cell activation (Fig. 5h and Extended Data Fig. 9c), myeloproliferation (Fig. 5i and Extended Data Fig. 9d), and tissue inflammation (Fig. 5j,k and Extended Data Fig. 9e) similar to those in Foxp3-deficient Foxp3GFPKO mice indicative of a loss of Treg function.