Alpha-1-microglobulin is a 27-kDa glycoprotein with immunosuppressive properties. A gene in the lipocalin cluster encodes alpha-1-microglobulin together with a Kunitz-type proteinase inhibitor, bikunin. The gene is translated into the alpha-1-microglobulin-bikunin precursor, which is subsequently cleaved and the two proteins secreted to the blood separately. Alpha-1-microglobulin is found in blood and in connective tissue in most organs. It is most abundant at interfaces between the cells of the body and the environment, such as in lungs, intestine, kidneys and placenta. Alpha 1-microglobulin is an immunomodulatory protein with a broad spectrum of possible clinical applications and seems a promising marker for evaluation of tubular function. Immunogen: Human and rat alpha-1-microglobulin