The overall objective of this project is to identify risk factors associated with the development of multiple myeloma (MM) by integrating epidemiologic, clinical and molecular information. We plan to invite MDACC patients with MM, as well as controls, to participate in this investigative case-control study. Controls will be selected from friends and spouses who accompany patients to the various MDACC clinics and will be matched to the cases on age (±5 years), gender, and ethnicity. We will obtain demographic, risk factor and clinical information along with a blood and buccal sample from all cases and controls. This study could have implications for prevention and subsequent reduction in the incidence of multiple myeloma. Collecting blood and buccal samples will allow us to study the role genetic susceptibility plays in MM risk. The specific aims are: