A, JTC-27 rat hepatoma cells were treated with the indicated concentrations of rOSM for 15 min. The phosphorylation levels of STAT1, STAT3, STAT5 as well as ERK1/2, p38 and Akt were detected via Western blot analysis. The blots were stripped and reprobed with antibodies recognizing the proteins irrespective of their activation status. B, HepG2 human hepatoma cells were exposed to 10 ng/ml hLIF or hOSM for 15 min. Western blots detecting the activation status of the indicated proteins were performed as described in A. C, Hepatoma cells from rat (JTC-27), human (HepG2) and murine (Hepa1c1c7) origin were treated with 10 ng/ml hLIF, hOSM, mOSM or rOSM for 15 min. Activation of the indicated proteins was detected via Western blot analysis as described in A. Additionally an α-tubulin loading control was included. Blots shown are representative for 3 or more experiments.