(a) Real-time RT–PCR analysis of relative HOPX mRNA expression in normal (n=12) and NPC (n=24) tissues. Mean±s.d.; Student’s t-tests. (b,c) Immunohistochemical staining (× 200) (b) and statistical analysis (c) of HOPX in Normal tissues (n=6), primary NPC tissues without (LN−, n=10) or with (LN+, n=10) regional lymph node metastasis and primary NPC tissues with distant metastasis (DM, n=10). Scale bar: 100 μm; mean±s.d.; Student’s t-tests. (d,e) The mRNA (d) and protein (e) levels of HOPX were measured via real-time RT–PCR and western blotting in NPEC and NPC cell lines. Mean±s.d.; *P<0.01 compared with NP69; Student’s t-tests. (f,g) HOPX methylation levels measured via bisulfite pyrosequencing analysis (f) and relative HOPX mRNA levels measured via real-time RT–PCR analysis (g) with (DAC+) or without (DAC−) DAC treatment in NPEC and NPC cell lines. Mean±s.e.m.; *P<0.01 compared with DAC−; Student’s t-tests. These data are representative of three independent experiments.