unusually large amount of free immunoglobulin L chains in the urine of patients with multiple myeloma; discovered by an English physician named Bence Jones.

The antibody of a single species produced in large amounts by a person with multiple myeloma, a tumour of antibody producing plasma cells.

a portion of the abnormal myeloma protein referred to as the "light chains."

A small protein made by plasma cells (white blood cells that produce antibodies). It is found in the urine of most people with multiple myeloma (cancer that begins in plasma cells).

A Bence Jones protein is a protein often found in the blood and urine of patients with multiple myeloma. The proteins are immunoglobulin free light chains (paraproteins) and are produced by defective plasma cell function. There are various rarer conditions which can produce Bence Jones proteins, such as Waldenström's macroglobulinemia and other malignanices.