HDAC9 and Hodgkins lymphoma: Pharmacologic inhibition/blockade of Histone deacetylase (HDAC) 11 enhances the expression of OX40L in Hodgkin lymphoma (HL) cells, and the HDAC inhibitor-induced OX40L inhibits the immunosuppressive function of interleukin 10 (IL-10)-producing Treg cells and alters cytokine secretion of HL cells to favour a Th1- and Th17-type response (25).