Since both cases of KITWT/PDGFRAWT/SDHWT lacked mutations of BRAF, RAS family members or NF1, the GIST of these two patients was classified KITWT/PDGFRAWT/SDHWT/RAS-PWT or quadrupleWT GIST. This evidence concerns the gene NF1 and gastrointestinal stromal tumor.