Several small molecular weight inhibitors were reported active in CTCL patients including HDAC inhibitor panobinostat (NCT01261247) (40), PI3K inhibitor duvelisib (41), immunomodulatory agent lenalidomide (42) or proteasome inhibitor ixazomib (43). Here, HDAC9 is linked to primary cutaneous T-cell non-Hodgkin lymphoma.