Our findings suggest that that ANXA2 knockdown may increase the radiosensitivity in NPC cells exposed to X-ray irradiation through activating the p38 MAPK-HSP27 signaling pathway, upregulating Bax expression and downregulating Bcl-2 expression, and ANXA2 overexpression may decrease the radiosensitivity in NPC cells exposed to X-ray radiation through inhibiting the p38 MAPK-HSP27 signaling pathway, downregulating Bax expression and upregulating Bcl-2 expression. The gene discussed is BAX; the disease is nasopharyngeal carcinoma.