FGF2 and gastrointestinal stromal tumor: Of note, IM stimulated secretion of FGF-2 from IM-resistant (e.g., GIST T-1R) cells over the 6-day culture period in a time-dependent manner (Figure 1C), whereas in IM-naive GIST T-1 cells, the maximal FGF-2 levels were detected at day 2 of IM post-treatment and were further declined (Figure 1C), thereby reflecting IM-induced cell death of IM-naïve GIST T-1 cells.