B2M and cadmium poisoning: The latter, however, is based on a handful of observations (20 normal, 15 with glomerular, and 15 with tubular pathology due to cadmium poisoning and hereditary syndromes) made 50 years ago at the dawn of the clinical chemistry and renal pathology and before the complex β2M-dependent mechanisms of protein transport in the kidney were deciphered (141).