MAP2K1 and glioblastoma: Interestingly, 45–57% of GBM cases tested, showed activating mutations in the EGFR gene, which is one of the main activators of Ras/Raf/MEK1/Erk1/2 signaling axis and it is found to be involved in proliferation, migration and invasion of brain cancer cells (1, 64, 65).