The oral class I/II HDAC inhibitor chidamide has been studied in 83 R/R PTCL patients in China in a phase II study, which included patients with PTCL NOS (34%), ALCL (22%), ENKTL, nasal type (20%), or AITL (13%). The gene discussed is HDAC9; the disease is mature T-cell and NK-cell non-Hodgkin lymphoma.