<prompt> Which of the following markers is specific for Gastro intestinal stromal tumors GIST?CD 117CD 34CD 23S-100  <response>: CD 117 is most specific marker for Gastrolintestinal stromal tumor, than CD 34. GIST has a universal expression of CD117. It can also be present in fibroblastic and endothelail tumors. Ref: M. Wasif Saif 2010, Chapter Gastrointestinal Stromal Tumors, In the book, Gastrointestinal Malignancies, Volume 1, Issue 1, USA, Page 152; Robbins Basic Pathology, 7th Edition, Page 826; Oncology: An Evidence Based Approach, 2006, Pages 413-14; Sternbergs-Diagnostic Surgical Pathology, 4th Edition, Page 1590 