DOG1 antibody expression has been reported to be a very sensitive and specific marker for gastrointestinal stromal tumor (GIST) cells. In studies of GIST cases with KIT mutations, DOG1 detected 11% more cases than CD117. As a result of its localization in the cell membrane, its absence in the majority of normal tissue and its presence in most GIST tissue, recent studies suggest that DOG1 may be a helpful target to aid in the diagnosis and assignment of appropriate treatment of GIST. DOG1 expression is seen in fewer cases of mesenchymal and epithelial tumors, seminomas and melanomas when compared with CD117.