IL6 and osteosarcoma: The total protein expression levels in each group of SaOS-2 osteosarcoma cells were determined by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) and Coomassie Brilliant Blue staining to eliminate the effects of differential protein expression on the comparison of phosphoprotein abundances; the protein expression levels derived from the whole cell lysates of the Con group, the Lob group, and the IL-6 group were similar (Fig. 1a).