Nature Communications, Published online: 15 June 2026; doi:10.1038/s41467-026-74483-1 Responses to immune checkpoint inhibitors in patients with relapsed or refractory extranodal natural killer/T-cell lymphoma (R/R ENKTL) remain limited. Here the authors report the results of a phase 1b/2 trial of liposomal mitoxantrone plus anti-PD-1 tislelizumab in patients with R/R ENKTL.