TNF and prion disease: Moreover, no studies about in situ variations in cytokine levels after glucocorticoid (GC) treatment in prion diseases have been previously published, despite the fact that it is well known that chronic administration of GC inhibits both innate and adaptive immune systems, reducing a great variety of pro-inflammatory cytokines [43], such as IL-1, TNF [44], IL-6 and IFNγ [45,46].