EIF4EBP1 and lung carcinoma: Irradiated xenografts of the two lung cancer types showed reduced levels of phosphorylation of 4EBP1 (P-4EBP1) indicating reduced mTOR activity (reduction by 81.0 ± 4.75% and 47.0 ± 3.20% in A549 and H1299 xenografts, respectively) (Figure 5A-B).