Systemic anaplastic large cell lymphoma (ALCL) is an aggressive CD30-positive, mature T-cell non-Hodgkin lymphoma (T-NHL), which can be divided into two entities according to the presence or absence of Anaplastic Lymphoma Kinase (ALK)-fusions, i.e., ALK-positive (ALK+) and ALK-negative (ALK−) ALCL1,2. The gene discussed is ALK; the disease is T-cell non-Hodgkin lymphoma.