In this work, using MIB-MS (19, 20), we explored a high percentage (296 of 518) of the human kinome in treatment-naive primary GIST specimens from 3 GIST subtypes (KIT mutant, PDGFRA mutant, and SDH-d GISTs) to identify potential targets. The gene discussed is SDHB; the disease is gastrointestinal stromal tumor.