IL2 and autoimmune disease: Apart from this, the survival and growth of Treg fundamentally depend on the availability of IL-2, constituting a vulnerable point in Treg biology (9, 10), and a relative deficiency or shortage of IL-2 can develop in autoimmune diseases leading to a disturbance of Treg homeostasis which further amplifies the vicious cycle of tolerance breach and chronic inflammation (24–26).