ALK and lymphoma: The PTCLs are divided into multiple subtypes including but not limited to PTCL–not otherwise specified (PTCL-NOS; 26%), angioimmunoblastic T-cell lymphoma (AITL; 18.5%), NK/T-cell lymphoma (10%), adult T-cell leukemia/lymphoma (ATLL; 10%), anaplastic large cell lymphoma (ALK)-positive lymphoma (ALCL; 7%), and ALK-negative ALCL (6%; Vose, Armitage, & Weisenburger, 2008).