Bence Jones protein
A protein that may be found in the urine of people with certain forms of protein disorders, such as amyloidosis and multiple myeloma. In most cases of multiple myeloma, a single type of intact (whole) immunoglobulin is produced in excess. In a minority of cases, only one section of an immunoglobulin called a "free light chain" is produced in large amounts. These excess free light chains are released into the bloodstream and since they are relatively small molecules, they are filtered by the kidneys and released into the urine. Another term for these excess free light chains in the urine is Bence Jones proteins.