Moreover, the HDAC inhibitor SAHA was found to synergize with JQ1 to suppress advanced pancreatic ductal adenocarcinoma effectively.[60] In addition, HDAC inhibitors have broad application prospects in combination with checkpoint inhibitors due to the ability of HDAC inhibitors to modulate the transcriptome of cancer and immune cells.[61] Therefore, CUL4B inhibitors are potential epigenetic therapy drugs. Here, HDAC9 is linked to pancreatic ductal adenocarcinoma.