The 5-year cumulative incidence of CNS relapse was 1.8% in PTCL-NOS, 0.7% in AITL, 5.4% in ALK+ALCL, 2.1% in ALK-ALCL and 3.7% in ENKL. This evidence concerns the gene ALK and mature T-cell and NK-cell non-Hodgkin lymphoma.