In previous evaluations of the immune response, mainly CD4+ T cells, B cells as well as IL-1β, IL-2, IL-6, TNF-α, lymphotoxin and IFN-γ have been detected in brain specimens from SSPE patients, which demonstrated cellular infiltrates, demyelination, gliosis and inflammatory activation [24–27]. This evidence concerns the gene IL2 and subacute sclerosing panencephalitis.