DOG1 (Discovered On GIST-1) is an immunohistochemistry (IHC) marker used primarily in pathology to help identify gastrointestinal stromal tumors (GISTs).

In this test, a tissue sample (usually from a biopsy or surgical specimen) is stained using antibodies against the DOG1 protein. If DOG1 is present in the tumor cells, the cells show a distinct membranous staining pattern under the microscope.