The Lymphoma Epidemiology of Outcomes (LEO) cohort is a prospective cohort study of newly diagnosed non-Hodgkin lymphoma (NHL) patients for use by researchers (internal and external to LEO) to advance the study of NHL prognosis and survivorship.  To achieve this objective, LEO promotes the sharing of data, biospecimens and other resources with internal and external investigators.  This section provides access to LEO Cohort Details for Researchers with summary tables describing cohort; LEO Questionnaires and SOP Manual; Guidelines for External Collaboration and the LEO Data Sharing Plan; Process for Approving a Collaborative Project; an online Resource Request Form.