PDGFRA and gastrointestinal stromal tumor: 9 West West RB RB Corless Corless CL CL Chen Chen X X Rubin Rubin BP BP Subramanian Subramanian S S Montgomery Montgomery K K The novel marker, DOG1, is expressed ubiquitously in gastrointestinal stromal tumors irrespective of KIT or PDGFRA mutation status The novel marker, DOG1, is expressed ubiquitously in gastrointestinal stromal tumors irrespective of KIT or PDGFRA mutation status Am J Pathol.