Multiple myeloma is a type of cancer that forms in a plasma cell, a type of white blood cell. Plasma cells are responsible for making antibodies that recognize and help in fighting germs and infections.
In people affected by Multiple myeloma the plasma cells multiplies unusually and accumulate in the bone marrow. As a result, the cells produce abnormal proteins (called immunoglobulin) rather than helpful antibodies. These cancer cells then releases too much protein into the blood and the bones which gradually spreads throughout the body causing organ damage.