The ability of exogenous FGF-2 to protect IM-naive GIST T-1 cells from IM treatment was also revealed by a substantial decrease of apoptotic (i.e., TUNEL-positive) cells in GIST cultures treated with IM in the presence of FGF-2 when compared to GIST cells treated with IM alone (Figure 5E,F). This evidence concerns the gene FGF2 and gastrointestinal stromal tumor.