In 2011, to investigate the mechanisms of the p53-mediated radioresponse in NPC, proteins from p53 knockdown (CNE-2sip53) and a paired control were subjected to 2-DE and MALDI-TOF-MS, and the 14-3-3σ, prohibitin, annexin-A1, Glutathione S-transferase P1, proteasome subunit and keratin-18 of differential radioresponsive proteins were related to p53 protein [90]. Here, KRT18 is linked to nasopharyngeal carcinoma.