简介:<正>Immunologicaltolerancetoselfisessentialformaintainingtheintegrityoftheorgansystems,anditsbreakdownmayleadtothedevelopmentofautoimmunediseases.Tolerancetoselfismaintainedthroughseveralmechanisms,whichincludenegativeselection,functionalinactivation(anergy)andsuppressionofautoreactivelymphocytes.However,onlynegativeselectionpermanentlyremovesautoreactivecellsthroughapoptosis.WhileithaslongbeenknownthatnegativeselectionrequiresaTcellreceptor(TCR)signal,itisunclearwhetheradeathligandsignalisalsoinvolved.TRAIL,thetumornecrosisfactor(TNF)-relatedapoptosis-inducingligand,isanewlydescribedmemberoftheTNFfamily.Unlikeotherdeathligandsof