A previous study revealed that maintenance treatment with chidamide after chemotherapy reduced relapse and improved survival in patients with PTCL (4), suggesting that post-transplant maintenance therapy with histone deacetylation inhibitors (HDAC) such as chidamide can further reduce the relapse rate and improve survival. The gene discussed is HDAC9; the disease is mature T-cell and NK-cell non-Hodgkin lymphoma.