Specificity: DOG1.1 is a sensitive and specific immunohistochemical marker for GIST, comparable with c-Kit, with the additional benefit of detecting c-Kit-negative GISTs. DOG1.1 is also a sensitive marker for unusual GIST subgroups lacking c-Kit or PDGFRA mutations. Immunogen: A synthetic peptide from human DOG-1 protein (MSDFVDWVIPDIPKDISQQIHKEKVLMVELFMREEQDKQQLLETCMEKERQKDEPPCNHHNTKACPDSLGSPAPSHAYHGGVL), conjugated to a carrier protein.