HDAC9 and primary cutaneous T-cell non-Hodgkin lymphoma: Suberoylanilide Hydroxamic Acid (SAHA), an HDAC inhibitor approved by the U.S. Food and Drug Administration for the treatment of cutaneous T-cell lymphoma, was taken as a positive control, which showed Kd values of 2.09 ± 0.45 μM for SAHA-PfHDAC-1 and 15.06 ± 0.75 μM for SAHA-hHDAC-1 (Fig. 1C and E).