MAPK3 and glioblastoma: Previous reports were able to show that ectopic expression of mSpry4 inhibits phosphorylation of overexpressed ERK2 [8,22] in 293 cells and Spry4 expression interfered with the FGF2 activation of ERK1/2 proteins in glioblastoma-derived cells [19], while Spry4 failed to influence FGF-induced ERK phosphorylation in pancreatic cells [23].