ALK and mature T-cell and NK-cell non-Hodgkin lymphoma: In ALCL-ALK+, NK/TCL, PTCL-NOS, and AITL, EZH2 overexpression was detected in the majority of cases: ALCL-ALK+ (13/14, 93%), NK/TCL (15/16, 94%), PTCL-NOS (15/16, 94%), and AITL (15/17, 88%).