The main features of AITL are: sCD3(-/dim), CD4(+), CD10(dim/+), PD-1(+); the main features of ENKTL-N are: sCD3(+), CD56(+); The main features of ALCL are: sCD3(-/dim), CD4(+), CD5 (–), CD30(+), HLA-DR(+). Here, PDCD1 is linked to anaplastic large cell lymphoma.