EIF4EBP1 and cancer: Furthermore, ΔL1CAM cells had decreased phosphorylation of ribosomal protein S6 (RPS6) at S235/S236 and eukaryotic translation initiation factor 4E-binding protein 1 (EIF4EBP1) at S65, well-characterized downstream substrates and markers for activated mTORC1, which regulates cell metabolism, protein and lipid synthesis, proliferation, and survival, leading to increased cancer progression and therapy resistance [18,19].