 Blood samples are collected periodically to evaluate antibody titers to recall antigens; serum IgG, IgM, and IgA levels; the proportion of circulating B-cells by phenotyping for CD19, CD20, CD22, CD23, CD4, CD8, and CD38; the ability of peripheral blood mononuclear cells to kill multiple myeloma cell lines or the patients own cryopreserved myeloma cells via cytotoxicity assays and ELISPOT assays; and human anti-mouse antibody responses to murine IgG2a OKT3. Bone marrow biopsies are also collected to analyze the phenotype of cells CD20, CD138-, CD27, CD22, etc. via flow cytometry and the proportion of plasma cells via flow cytometry and hematoxylin-and-eosin staining. 