ROCHESTER, Minn. — A Mayo Clinic-led group of researchers has discovered three subgroups of a single type of non-Hodgkin lymphoma that have markedly different survival rates. These subgroups could not be differentiated by routine pathology but only with the aid of novel genetic tests, which the research team recommends giving to all patients with ALK-negative anaplastic large-cell lymphoma (ALCL). Findings are published in the journal Blood.