SDHB and gastrointestinal stromal tumor: Gastrointestinal stromal tumor (GIST), the most common mesenchymal malignancy of the gastrointestinal tract, has been classified into five major molecularly subtypes through next-generation sequencing (NGS) including classical KIT/PDGFRA-mutant, SDH-deficient, NF1-assoicated, BRAF-mutant, and NTRK3-fusion GISTs (1).