Multiple myeloma (MM) is always preceded by a pre-malignant asymptomatic phase, monoclonal gammopathy of undetermined significance (MGUS). Given the incurable nature of MM it is vital to study the development of MM from MGUS to help in identifying early diagnostic and treatment opportunities. This project aims to determine if glutamine metabolism in plasma cells is vital for their survival and whether it is associated with the progression of MGUS to MM. It will involve the utilization of stable isotope resolved metabolomics methods to evaluate the utilization of glutamine by the bone marrow plasma cells in MGUS compared to MM. Patients with MGUS and MM will undergo bone marrow aspirations after being infused with 13-carbon labelled glutamine. The subsequent bone marrow plasma cells obtained from these aspirates will undergo GC-MS assessments of the TCA cycle isotopomers. This will help determine the differences in the utilization of glutamine by the bone marrow plasma cells between MGUS and MM.