HDAC9 and neoplasm: Targeting HDAC5 impairs the suppressive activity and de novo induction of Tregs, but also inhibits the ability of CD8+ T cells to bind to their cognate receptors.386 In contrast, the class-I-specific HDAC inhibitor entinostat reduces Treg cell activity, leading to enhanced antitumor immunity.387 These results indicate that different HDAC inhibitors have different effects on tumor immunity, suggesting the potential role of selectively targeting HDACs to improve antitumor immunity.