Bisulphite genomic sequencing of NPC cells, tumor biopsies and NNEs. Bisulphite genomic sequencing of the methylation status of the 31 CpG sites within the TFPI-2 promoter in 2 NPC cell lines (CNE2 and C666-1), 2 NPC biopsies (NPC24 and NPC34) and 1NNE biopsy (NNE7). Five randomly selected clones were sequenced for each sample. Open and filled circles represent unmethylated and methylated CpG sites, respectively. Circles were partially filled according to the percentage of methylation of the CpG site. The frames show the CpG pairs covered by methylation-specific PCR primers.