Droxinostat is a selective histone deacetylase (HDAC) inhibitor, primarily targeting HDAC6 and HDAC8 with IC50 values of 2.47 µM and 1.46 µM, respectively. It demonstrates over 8-fold selectivity against HDAC3 and shows no activity against several other HDAC isoforms. This compound is a valuable research tool for studying epigenetic mechanisms in both cellular and animal models of cancer and neurological diseases.