B2M and Nephropathy: Our ELISA results shows that the median concentration of B2M (7.8 μg/mg creatinine) in urine of healthy subjects is ~116-fold higher than CC16 (0.067μg/mg creatinine), and the median concentration of B2M (26.9 μg/mg creatinine) in urine of WDM-NP (nephropathy) subjects is ~302-fold higher than CC16 (0.089μg/mg creatinine).