CES1 and rectal cancer: Genomic analysis in TCGA-READ further demonstrated that CES1 expression was positively associated with copy number status, whereas coding-sequence mutations in CES1 were infrequent, suggesting dysregulation primarily through copy-number and transcriptional mechanisms.<h4>Conclusion</h4>This integrative computational and experimental study identifies CES1 as a predictive biomarker and copy number-linked regulator of radiosensitivity in rectal cancer.