TP53 and nasopharyngeal carcinoma: In 2006, to detect proteins that were associated with the function of p53 in NPC, proteins from the p53 knockdown human NPC CNE-2 cell line were compared with the control in high-throughput screening by MALDI-TOF-MS and electrospray ionization-quadruple time-of-flight mass spectrometry (ESI-Q-TOF-MS) [75].