EIF4EBP1 and glioblastoma: In agreement, Martínez-Sáez et al. used immunohistochemistry to investigate 4E-BP1 in 104 diffuse infiltrating astrocytomas including diffuse astrocytomas (grade II, n = 19), anaplastic astrocytomas (grade III, n = 25), and GBM (grade IV, n = 60).