HDAC9 and renal carcinoma: In similar experiments, Okubo et al. described nelfinavir-mediated dose-dependent accumulation of sub-G1 DNA content in renal cancer cells with concomitant reduction in cyclin D1 and CDK4—a phenomenon further aggravated by the addition of panobinostat, an inhibitor of histone deacetylases (HDAC) [28,29].