In this study, 19 patients with relapsed/refractory peripheral T-cell lymphoma were treated with the combination of Pembrolizumab and Romidepsin, the best complete response rate and the best objective response rate are 42% and 47%, respectively.[16] A clinical trial evaluating PD-1 antibody and HDACi is ongoing in refractory or relapsed ENKTL (NCT03820596). This evidence concerns the gene PDCD1 and peripheral T-cell lymphoma, not otherwise specified.