We explored combining this TRAIL NP therapy with histone deacetylase (HDAC) inhibitors, which have shown promise in sensitizing resistant cells to TRAIL.19, 20, 21, 22, 23 We hypothesized that the bystander effect of secreted TRAIL to non-transfected cells combined with HDAC inhibitor sensitization could result in a potent yet cancer-specific non-viral TRAIL gene therapy. This evidence concerns the gene HDAC9 and cancer.