IL2 and Parkinson disease: Recently, many studies showed that damaged substantianigra striatum regions had T, B lymphocyte cell infiltration in PD, and damaged regions had high levels of inflammatory factor, tumour necrosis factor α (TNF-α), interleukin 1β (IL-1β), IL-1, IL-2, IL-4, IL-6 and some chemokines [21,22,23,24].