Radical radiotherapy remains the standard treatment for non-metastatic nasopharyngeal carcinoma (NPC). However, a considerable proportion of patients still experience therapeutic failure due to the emergence of radioresistance. The molecular mechanisms underlying this resistance are not fully elucidated, underscoring the need for new biomarkers and therapeutic targets to increase radiosensitivity and improve treatment outcomes. Gene and protein expression were assessed using RT-qPCR, Western blot, and IHC. Cell viability, proliferation, and apoptosis were evaluated using the CCK-8 assay, colony formation assay, and flow cytometry, respectively. The binding of BHLHE40 to the CAV1 promoter was examined using ChIP and dual luciferase assay. An