IL4 and viral encephalitis: Positive immunostaining for IL-4, IL-10, IL-33, IL-37 and TGF-1β, indicative of the presence of a Th2 response, has already been reported in other viral encephalitis cases and may be related to simultaneous development of suppressive agents and an antiviral response, which are necessary for elimination of the infectious agent without causing major inflammatory damage46,47,49,54,55.