PRDM7 and cancer: To further verify the overabundance of epigenetic mutations in cancer tissues, we picked a gene PR/SET domain 7 (PRDM7) which was the only gene related to CpGs tested in pyrosequencing (cg05270750), and analyzed DNA methylation and gene expression data of the gene in tumor tissues and normal adjacent tissues using The Cancer Genome Atlas (TCGA) [16] data downloaded from Wanderer [17].