EGFR and glioblastoma: For this purpose, GBM cells were transiently transfected with plasmids encoding a mutant EGFR bearing a phenylalanine (F) substitution at tyrosine (Y) residue 845 (EGFRY845F plasmid for U87MG and U87MG-EGFRwt cells, EGFRvIIIY845F plasmid for U87MG-EGFRvIII cells).