The major subtypes, in descending order of incidence, are PTCL, not otherwise specified (PTCL-NOS, 25.9%), angioimmunoblastic T-cell lymphoma (AITL, 18.5%), extranodal NK/T-cell lymphoma, nasal type (ENKTL, 10.4%), and adult T-cell leukemia/lymphoma (ATLL, 9.6%), followed by anaplastic large cell lymphoma (ALCL, ALK-positive and ALK-negative combined, 12.1%) (1). This evidence concerns the gene ALK and lymphoma.