NF1 and gastrointestinal stromal tumor: The pathogenesis of GIST involve gain-of-function mutation in KIT (accounts for 75–80%), platelet-derived growth factor receptorα(PGFRA) (< 10%), or gene abnormalities including succinate dehydrogenase (SDH)-deficiency, the mutations of neurofibromin 1 (NF1), Kirsten rat sarcoma viral oncogene homolog (KRAS) and Harvey rat sarcoma viral oncogene homolog (HRAS) pro-oncogenes [11–13].