More rarely, SDHBIHC-/SDHAIHC+ subgroup may include sporadic KITWT/PDGFRAWT GIST characterized by SDHB, −C or D mutations (most of them germline, and in few cases by SDHA mutations), arising mainly from the stomach, with a lesser female prevalence, but histologically similar to SDHAIHC- GIST [15]. This evidence concerns the gene SDHB and gastrointestinal stromal tumor.