The study conducted by Marquard and collaborators in cutaneous T-cell lymphoma (CTCL) patients reported a high expression level of HDAC1, HDAC2, and HDAC6, and an association between the levels of HDAC2 and histone H4 acetylation and tumor aggressiveness. Here, HDAC1 is linked to primary cutaneous T-cell non-Hodgkin lymphoma.