The prevalence of cadmium-related kidney dysfunction among population groups residing in cadmium contaminated areas in China report reveal a dose-response relationships between urinary-Cd and renal tubular dysfunction such as urinary beta-2-microglobulin or N-acetyl-beta-D-glucosaminidase-NAG or urinary albumin, a biomarker of glomerular kidney dysfunction. This evidence concerns the gene B2M and renal tubule disorder.