ALK and angioimmunoblastic T-cell lymphoma: The distribution of common histological subtypes was as follows: 317 (51.0%) patients had ENKTL (Fig. 1a), 118 (19.0%) had AITL (Fig. 1b), 81 (13.0%) had PTCL-NOS (Fig. 1c), 31 (5.0%) had anaplastic lymphoma kinase (ALK)-positive ALCL (Fig. 1d), 15 (2.4%) had ALK-negative ALCL, and 13 (2.1%) had primary cutaneous ALCL (Table 2).