EIF4EBP1 and neoplasm: To confirm this, we performed IHC on the tumours to look for activation of downstream effectors of both of these pathways—phosphorylated ribosomal protein S6 and phosphorylated 4EBP1 for the PI3K/AKT/mTOR pathway, and phosphorylated ERK1/2 for the Ras/Raf/MEK/ERK pathway.