Suppression of GRP78 expression in IGF-1R deficient cells under basal growth conditions is independent of the transcription factor FOXO1. A: Representative immunoblots for endogenous GRP78 protein, FLAG-tag, and β-actin in 293T cells transfected with the empty vector PCDNA or vector expressing constitutively active FLAG-tagged FOXO1-AAA. B: Representative immunoblot for FOXO1 protein expression in R+ and R− cells transduced with lentivirus expressing control shRNA or FOXO1 shRNA (shFOXO1). C: Grp78 mRNA expression measured in R+ and R− cells transduced with lentivirus expressing FOXO1 or control shRNA by quantitative real-time RT-PCR. D,E: Representative immunoblot and quantitation for GRP78 protein expression in R+ and R− cells transduced with lentivirus expressing FOXO1 or control shRNA. The values are presented as mean ± SE, n=2-6, ***p≤0.001 compared to untreated R+ group, +++p≤0.001 compared to R+ shRNA group.