<prompt> GIST associated marker is?CD 117CD 34CD 23S-100  <response>: Ans. is a i.e., CD 117 The most useful marker of GIST is C-kit CD-I 17. Other markers are CD 34, smooth muscle actin and vimentin. Although CD 117 c kit is considered the most specific marker for GIST, it is not pathognomonic of GIST as other tumors may also express CD 117. These tumors include mast cell tumor, germ cell tumors seminomas, leukemias, malignant melanoma, angiolipomas, and some sarcomas. 