Is required for GIST882 cell survival. In contrast,as GIST-T1 cells have no detectable endogenous IGFBP3, we overexpressed IGFBP3 using an adenoviral gene expression system. Infection with an adenoviral vector expressing IGFBP3 (Ad-IGFBP3) but not empty vector (Ad-EV) resulted in high, sustainable levels of IGFBP3 (Figure 3A). IGFBP3 overexpression in GIST-T1 cells resulted in a dose-dependent los