All of them were gastric, non-NF1-related, at-least-in-part epithelioid (see Additional file 1: Figure S1, which shows a typical SDH-negative GIST from our series) and WT for KIT, PDGFRA, KRAS, and BRAF. All these GISTs harbored mutations in one of the subunits of SDH, namely, SDHA in seven cases, SDHB in one case, and SDHC in one case. This evidence concerns the gene PDGFRA and gastrointestinal stromal tumor.