G6PD and gastrointestinal stromal tumor: We first measured key regulatory enzymes expression in glucose metabolism, including hexokinase (HK), 6-phosphofructokinase-1 (PFK-1), citrate synthase(CS), isocitrate dehydrogenesa (IDH), glucose-6-phosphate dehydrogenase (G6PD) and phosphogluconate dehydrogenase(PGD), using quantitative reverse transcriptase-PCR (qRT-PCR) in GIST-T1 and GIST-882 cell lines and 31 sensitive and 17 resistant tumor tissues from GIST patients.