CBX7 and gastric carcinoma: In consideration of above observation that CBX7 is downregulated in primary gastric carcinomas with p16 methylation and CBX7 knockdown does not induce demethylation of p16 in PC3 cells, it is likely that CBX7 upregulation may be sufficient for induction or maintenance of H3K9me3, but not for the establishment of DNA methylation within the p16 locus.