The patients received the following maintenance therapy for 2 years: Chidamide (30 mg qW14) + anti-PD-1 (200 mg q3w) and was maintained on remission by bone marrow (BM) evaluation and minimal residual disease (MRD) detected by flow cytometry, which suggest the combination of anti-PD-1 antibody and Chidamide may serve as a promising new Chemo-free therapeutic strategy in the maintenance stage treatment of T-ALL. This evidence concerns the gene PDCD1 and acute lymphoblastic leukemia.