In detail, ENKTLs mainly composed of pleomorphic large cells with diffuse CD30 expression bear a striking resemblance to ALCL; conversely, ALCLs with intensive CD56 staining might also be misdiagnosed as ENTKL, especially those involving the nasal cavity and the surrounding areas with negative ALK staining or without ALK investigation. The gene discussed is ALK; the disease is anaplastic large cell lymphoma.