Pathology G.I.T. 88ea4e21 Immuno-marker for GIST is? A CD 117 B CD 4 C CD 100 D CD45 High-Yield Explanation Ans. is 'a' i.e., CD 117 * CD 117 (c kit) is considered the most specific marker of GIST.* Other markers are CD 34, smooth muscle actin and vimentin.