Stimulator of interferon genes (STING) is a component of the innate immune response that binds to cyclic dinucleotides, which are bacterial second messengers, lEAding to activation of NF-B and transcription of immunomodulatory genes, including type I interferon (IFN).1,2,3,4 The H232 variant of STING is found at a 13.7% frequency in the 1000 Genome Project.5 The SNP variant R232 (Item No. 22816) is the most common variant in the human population, found at a frequency of 57.9%. Various mutations in STING either reduce or incrEAse its activity. Gain-of-function mutations in STING, including R284M (Item No. 23594) and V155M, lEAd to constitutive activation and enhancement of the type I IFN response.5,6 The V155M mutation is associated with a systemic inflammatory condition, including pulmonary fibrosis and autoimmune factors.6 Mutations that reduce STING activity include K224R (Item No. 23593), which reduces ubiquitination of STING thereby disrupting its localization within the cell, and the double mutation G230A, R293Q (Item No. 23592), which reduces the IFN response.5,7 A T596A mutation present in the mouse strain Goldenticket lEAds to a complete loss of STING protein and lack of a type I IFN response to infection by Listeria.8Technical InformationSynonymsEndoplasmic Reticulum Interferon StimulatorERIShSTINGMITAMPYSStimulator of Interferon GenesTMEM173Purity70% estimated by SDS-PAGESourceRecombinant N-terminal His-tagged STING catalytic domain purified from E. coliAmino Acids138-379 (N-terminal truncation), H232 variantMW28.8 kDaFormulation50 mM HEPES, pH 8.0, 150 mM sodium chloride, 10% glycerolUniProt Accession Q86WV6