Fig. 1

a, b Expression of Syk and phosphorylated Syk in different cell lines and patient samples. a Syk was immunoprecipitated from MM cell lines and primary MM cells. Immunoprecipitates were subjected to Western blotting using specific antibodies. Primary myeloma cells were obtained from peripheral blood of myeloma patients with plasma cell leukemia (PCL, purity >90%). Displayed is a representative immunoblot of Syk and pSyk in the absence of Syk inhibitors which shows Syk expression in the utilized MM cell lines and PCL-cells. b and c Addition of Syk inhibitors (Piceatannol, R406 and Bay61-3606) reduce the expression of pSyk in MM cell lines and PCL cells. Ponceau S staining was performed to confirm equal amounts of protein.