HK1 and gastrointestinal stromal tumor: In this study, we aimed to identify 1) the relationship between maximum standardized uptake value (SUVmax) on preoperative 18F-FDG PET/CT with GLUT and HK expression in GISTs, 2) the specific isoforms of GLUT and HK that are upregulated according to GIST tumor risk grade, and 3) alterations in the expression of various glycolytic enzymes according to tumor risk grade.