New studies have shown that histone deacetylase inhibitors can help as a novel antitumor drugs in cotherapy with conventional radiochemotherapy especially in CTCL. Several studies and clinical trials have used specific and non specific HDACi. Results were sometime promising and sometimes futile. The novel drug has taken the FDA approval for the treatment of cutaneous T cell lymphoma and leukemia.in Europe the drug is not yet approved. Best outcomes came in combination with conventional therapy. Toxicity was found as well.