MAPK3 and osteosarcoma: Western blot analysis and immunohistochemical staining were performed to verify the results of the phosphoproteomic and subsequent bioinformatic analyses, and the levels of p-filamin-C, AKT1 and p-ERK1/2 in the rhIL-6-pretreated osteosarcoma cells were found to be higher than those in the cells treated with lobaplatin alone, while lower expression of p-JNK and no significant change in the level of p-P38 were observed.