HDAC1 and diffuse large B-cell lymphoma: Overexpression of HDAC1, HDAC2, and HDAC6 and of higher acetylation levels of histone H4, with respect to the normal lymphoid tissue, have been reported by immunohistochemical studies conducted in patients with peripheral T-cell lymphoma (PTCL), and diffuse B large cell lymphoma (DLBCL) [61].