Here we investigated whether the previously identified crosstalk between HDAC and DOT1L occurs in human CTCL lines, addressing the question whether the crosstalk between DOT1L and HDAC1 observed in mouse T cells mediates the therapeutic effect of pan-HDAC inhibition in human CTCL. The gene discussed is HDAC1; the disease is primary cutaneous T-cell non-Hodgkin lymphoma.