<prompt> Most common organ involved in GIST is?IleumDuodenumColonStomach  <response>: Ans. is d i.e., Stomach GISTs are the most common mesenchymal neoplasm of gastrointestinal tract. GIST represents a distinct group of gastrointestinal tumors that originate from the interstial cells ofcajal which control gastrointestinal peristalsis. GISTs can occur anywhere in the gastroinstestinal tract; the most common site being the stomach followed by small intestine. 