Systemic CD30+/ALK− ALCL lack an ALK gene rearrangement and subsequently any ALK expression, but has other alterations, such as 6p25 rearrangements involving the IRF4/DUSP22 locus (the same as pcALCL which are negative for ALK expression, as well). The gene discussed is TNFRSF8; the disease is anaplastic large cell lymphoma.