It is well known that HDAC inhibitors are potent anticancer drugs in hematopoietic malignancies, including lymphoma.19 — 21 The aim of using HDAC inhibitors is to restore normal histone modification patterns through inhibition of various components of the
epigenetic machinery.22, 23 In B - cell lymphoma, HDAC inhibitors can rescue deficits in histone acetylation induced by EP300 / CREBBP mutations, 24 rendering tumor cells more sensitive to suberoylanilide hydroxamic acid.25 This can explain why chidamide also has favorable efficacy on PTCL - NOS
patients bearing EP300 / CREBBP mutations.