As it is crucial to differentiate between ALK− ALCL cases from primary cutaneous ALCL (C-ALCL) and those involving the digestive tract from CD30+ enteropathy-associated lymphomas or other intestinal T-cell lymphomas, which can be difficult to do based on lymph nodes alone, it may be useful to explore patient histories for any associated lesions; this could indicate nodal involvement by C-ALCL primary cells. The gene discussed is TNFRSF8; the disease is lymphoma.