In general, the average methylation level of the 29 genes was 8.20% in tumor and 7.13% in normal tissue (P = 4.30E-21), and the average methylation level in 7 genes (ATRX, DKC1, NBS1, RAD50, RAD51D, RTEL and TRF1) was larger than 10%. This evidence concerns the gene RTEL1 and neoplasm.