In addition, ANXA2 knockdown causes G2/M cell-cycle arrest, an increase in the apoptotic rate, a reduction in the formation rate of cell colonies and activation of the p38 MAPK-HSP27 pathway in NPC cells post-exposure to X-ray irradiation, and ANXA2 overexpression results in abrogation of the G2/M cell-cycle arrest, a reduction in the apoptotic rate, an increase in the formation rate of cell colonies and suppression of the p38 MAPK-HSP27 pathway in NPC cells post-exposure to X-ray radiation. The gene discussed is ANXA2; the disease is nasopharyngeal carcinoma.