Thus, we determined the expression of Cyclin B1 and CDK1 proteins, and Western blotting analysis revealed that ANXA2 knockdown caused a reduction in the Cyclin B1 and CDK1 expression, while ANXA2 overexpression resulted in elevated Cyclin B1 and CDK1 expression in NPC cells exposed to X-ray irradiation. The gene discussed is CDK1; the disease is nasopharyngeal carcinoma.