<prompt> What is false about GIST ?Associated with NF 1Most common site is stomachAssociated with CD 117Least common mesenchymal neoplasm of gastrointestinal tract  <response>: Ans. is d i.e., Least common mesenchymal neoplasm of gastrointestinal tract Gastrointestinal stromal tumors GISTs GISTs are the most common mesenchymal neoplasm of gastrointestinal tumor. GIST represents a distinct group of gastrointestinal tumors that originate from the interstial cells of cajal which control gastrointestinal peristalsis. GISTs can occur anywhere in the gastroinstestinal tract; the most common site being the stomach followed by small intestine. 