Sun et al. reported that the presence of the high PD-L1+ group (46%) including PD-L1+ tumour cells, resulted in significantly poorer prognosis compared with presence of the low PD-L1+ group (54%) in 144 patients with AITL, PTCL-NOS, ALK+ and ALK− sALCL (p < 0.05) [18]. This evidence concerns the gene ALK and mature T-cell and NK-cell non-Hodgkin lymphoma.