Three hydroxamate-type pan-HDAC inhibitors have been approved by the US Food and Drug Administration (FDA) to date for the treatment of the following cancers: SAHA for the advanced forms of cutaneous T-cell lymphoma (CTCL)5,6,32; Belinostat (Beleodaq) for refractory peripheral T-cell lymphoma (PTCL)33; Panobinostat (Farydak) for the combinatorial treatment of multiple myeloma34. Here, HDAC9 is linked to primary cutaneous T-cell non-Hodgkin lymphoma.