SDHC and gastrointestinal stromal tumor: The other GISTs without KIT or PDGFRA mutations (10–15%) are defined as KIT/PDGFRA-WT GISTs, which include succinate dehydrogenase-deficient GIST (SDH-deficient GIST) (< 10%) that caused by SDHA/B/C/D mutations or SDHC promotor hypermethylation modifications, and succinate dehydrogenase-competent GIST (SDH-competent GIST) (< 5%) that caused by other somatic gene mutations or gene fusions, such as neurofibromatosis type 1 (NF1) (< 2%), B-raf proto-oncogene (BRAF) (< 1%) and rat sarcoma viral oncogene (RAS) (< 1%) gene mutations, and other GISTs with unknown mutations [15, 17, 18].