In a previous study to determine how imatinib exerts its anti-tumor effects, we demonstrated that insulin-like growth factor binding protein-3 (IGFBP3) expression is up-regulated after imatinib treatment in the imatinib-responsive GIST cell line GIST882 as well as KIT-expressing tumor samples [12]. This evidence concerns the gene IGFBP3 and gastrointestinal stromal tumor.