Effect of IRS-1 targeting on LIF-mediated PI3K depending signals. A: Western blot showing IRS-1 protein expression (upper part), Akt phosphorylation on serine 473 (middle part), and total Akt protein (lower part), in parental, control (NT), and IRS-1 targeted ES cells. B: Same experiment as in (A) to detect phosphorylation of GSK-3β on serine 9, as well as total amount of GSK-3β protein. C: IRS-1 targeting has no effect on LIF-induced STAT-3 phosphorylation. Total amount of STAT3 protein was used as loading control. D: Western blots showing the levels of both Id-1 and Id-2 protein expression. Grb-2 protein levels were used as loading control. Figures are representative of three independent experiments.