MDH2 and nasopharyngeal carcinoma: The expression of COMT (P = 0.012), DUT (P =0.040), GMPS (P =0.043), MDH1 (P = 0.039), MDH2 (P = 0.020), NME1 (P =0.029), PAICS (P =0.011), POLR2I (P =0.039), PTGS2 (P =0.034) and UCK2 (P =0.029) increased the risk of NPC, while PLCB2 (P = 0.048) was a protective factor (Fig. 7C).