Histone deacetylases (HDACs), as epigenetic modifiers, are essential for gene transcriptional
activities. The alternation of HDACs expression, mutation and/or inappropriate recruitments has
been discovered in a broad range of tumors contributing to the tumorigenesis through a serial of biological
pathways. HDACs, therefore, are characterized as promising cancer therapeutic targets, and their
inhibitors are under rapid development. Here, we discuss HDAC inhibitors in terms of their functional
mechanism establishing the anti-tumor effects and potential clinical applications including the
synergistic effects in combinational treatment.