In a comparative study on radioresistant and sensitive control NPC cell lines, upregulation of non-metastatic clone 23, isoform H1 (Nm23 H1), maspin, GRP78, and manganese superoxide dismutase (Mn-SOD) and downregulation of 14-3-3 protein sigma (14-3-3σ) and annexin A1/A3 were found to be associated with radio-resistance [131,146,147,149,150]. This evidence concerns the gene SOD2 and nasopharyngeal carcinoma.