SOD2 and nasopharyngeal carcinoma: Among these proteins, Mn-SOD, ERp29, HSP27 and GST ω1 were up-regulated in the RR NPC tissues; TSP-1, PKM2, human electron transfer flavoprotein, MRP-14, DJ-1, GMFG, prohibitin and cytochrome c oxidase were down-regulated in the RR NPC tissues.