However, the fact that high 4E-BP1 expression can be also observed in some tumor samples and cell lines without chr8 gains may hint that other factors may also contribute to its high expression and suggest that high 4E-BP1 expression may serve as a more robust predictive biomarker for response to CDK4/6 inhibitors than chr8 gains per se. This evidence concerns the gene EIF4EBP1 and neoplasm.