GDF15 and brain cancer: However, the fact that MEK1/Erk1 pathway and GDF15 expression are also necessary for the migration of uncompressed A172 cells but not for that of uncompressed H4 cells, suggest for the first time that the presence of compressive forces in brain tumors can de novo activate MEK1/Erk1 pathway to promote the aggressiveness of brain cancer cells rendering this pathway along with GDF15 molecule as potential targets for the compression-induced brain tumor progression.