CUBN and plasma cell myeloma: Light chains are more challenging to detect than complete Igs.24 The SFLC assay has increasingly been used and tracks well with proteinuria in individual patients.25,26 The greater sensitivity when compared to urine analysis has brought forth the widespread use and incorporation of SFLC measurements into multiple guidelines for the management of myeloma; most recently it is a myeloma defining event in asymptomatic patients.9,27 All the study participants had a serum protein electrophoresis and a UPEP but surprisingly only a few had SFLCs.