Western blot analysis of extracts from CHO cells, untreated or insulin-treated following pretreatment with wortmannin (PI3 kinase inhibitor), rapamycin (mTOR inhibitor) and/or U0126 (MEK inhibitor) as indicated, using PathScan® Multiplex Western Cocktail I to detect phosphorylation of p90RSK, Akt, p44/42 MAPK and S6 ribosomal protein.