MAPK3 and glioblastoma: Next, we inhibited MEK/ERK1/2 activation in PBX3-overexpressed cells by U0126 and activated MEK/ERK1/2 pathway in PBX3-downregulated cells by PMA to determine whether PBX3-mediated GBM cell migration, invasion and mesenchymal transition were dependent on MEK/ERK1/2 pathway.