You can view the entire document as a PDF by clicking on the PDF icon on the right or by requesting a free hard copy from the Foundation.

Myeloma is a cancer of the plasma cells in the bone marrow. Plasma cells produce antibodies, also known as immunoglobulins, which are proteins that help fight infection. Each type of plasma cell produces only one type of immunoglobulin. There are many different types of plasma cells in the body, resulting in the production of a variety of different immunoglobulins.

In multiple myeloma, one particular type of plasma cell is duplicated a very large number of times, causing excess production of one type of immunoglobulin, which is referred to as a monoclonal protein, or M-protein. M-protein is also called myeloma protein, paraprotein, or the M-spike. The identification of an M-protein is important for diagnosis, and the measurement of its level is an aid for monitoring the effectiveness of treatment.