NCIt definition : Human immunoglobulin kappa and/or lambda light chains detected in their free form
in serum or urine samples as a result of overproduction by plasma cells due to neoplastic
proliferation. Detection of immunoglobulin light chains in concentrations that exceed
that of heavy chains is associated with plasma cell neoplasms.;
Alternative definition : NCI-GLOSS: 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).;