Actually, from preclinical research to clinical data, combination HDAC inhibitor with ICB immunotherapy can overcome resistance to ICB treatment alone including breast and pancreatic cancers, metastatic uveal melanoma, recurrent or metastatic squamous cell carcinomas of the head and neck, and metastatic non-small cell lung cancer [5, 7–9]. Here, HDAC9 is linked to familial pancreatic carcinoma.