DES and gastrointestinal stromal tumor: However, desmin (20 patients; 52.6%), cytokeratin (19 patients; 73.1%), S‐100 protein (24 patients; 96%), CD34 (n = 20; 95.2%), CD117 (n = 18; 100%), and myogenin (n = 2; 100%), discovered on GIST (DOG1, n = 2; 100%), usually stained negatively in patients with IMT.