In our study, we found that overexpression of CBX3 gene resulted in HP1γ production, and up-regulated the mRNA and protein levels of CDK1 and PCNA, suggesting a transcriptional activation mechanism may be involved in the HP1γ-mediated regulation of CDK1 and PCNA expression in PAAD. The gene discussed is PCNA; the disease is pancreatic adenocarcinoma.