BIRC3 and glioblastoma: Indeed, pretreatment of U87 human GBM cell lines with a PI3K pan-inhibitor, LY294002 prior to irradiation with 4 Gy resulted in dose-dependent blockade of irradiation-induced up-regulation of BIRC3 (c-IAP2) expression by RT-PCR (Fig. 3a; P < 0.01).