My research focuses on the epidemiology of hematopoietic malignancies, on oncogenic virus infections, and on the assessment of immune dysfunction for epidemiologic studies. My primary active research projects are prospective evaluations of lifestyle correlates of energy balance (anthropometric measures, physical activity, diet), other immune-modulating lifestyle factors, and biomarkers of growth factor, cytokine and other endogenous hormone dysregulation in the etiology of multiple myeloma (MM) and lymphoma. I conduct studies in the Nurses' Health Study (NHS) and the Health Professionals Follow-up Study (HPFS) populations at the Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, and in collaborative contexts, including with colleagues in the Dana-Farber/Harvard Cancer Center Lymphoma and Myeloma Program, the International Lymphoma Epidemiology (InterLymph) Consortium, the International Multiple Myeloma Consortium (IMMC) and the Lymphoid Malignancies Working Group (LMWG) of the NCI Cohort Consortium. As a former co-leader of the LMWG and former Chair of IMMC and of the Infections and Immunology Working Group of InterLymph, I have helped to facilitate some of the first pooled studies of risk factors for MM, as well as cross-consortium communication to nurture further collaboration on etiologic research. I represent the NHS and HPFS cohorts in a large international consortium (formed among InterLymph and LMWG member studies) conducting a genome-wide association study of NHL.