Human mesothelin, also known as CAK1 and MSLN, is a cell-surface protein expressed on normal mesothelial cells lining the pleura, pericardium, and peritoneum. It is expressed as a 70 kD pre-cursor protein with a furin cleavage site, which produces two products: 1) megakaryocyte potentiating factor (MPF) (30 kD); and 2) mesothelin (40 kD). MPF is a cytokine which is released. Mesothelin, for the most part, is membrane-bound by a glycosyl-phosphatidyl inositol linkage and has three glycosylation sites. Soluble mesothelin is believed to result from proteolytic cleavage to release it from the membrane linkage or from alternative splicing of the mesothelin gene.The normal function of mesothelin is not known. Mice knockouts produced no obvious phenotypes with normal growth and reproductive parameters.However mesothelin is overexpressed by cancer cells, particularly in mesotheliomas, ovarian adenocarcinomas, pancreatic adenocarcinomas, squamous cell carcinomas, and lung cancers. It binds to MUC16/CA-125, a cell surface mucin and ovarian cancer biomarker, and has been speculated to be involved in peritoneal dissemination of ovarian cancer cells. Mesothelin has also been shown to be elevated in the serum of cancer patients compared to normal. As such, it has become the focus of cancer research in the areas of diagnostics, immunotherapy, and cancer vaccinology. For example, SS1P is a recombinant immunotoxin that targets mesothelin-expressing cancer cells. Its anti-mesothelin Fv domain confers specificity, while its Pseudomonas exotoxin domain results in cell death. This potential drug has already finished stage I clinical trials.BioLegend's LEGEND MAX(TM) Human Mesothelin ELISA Kit is a sandwich Enzyme-Linked Immunosorbent Assay (ELISA), in which, a human mesothelin-specific monoclonal antibody is pre-coated on a 96-well strip-well plate.BioLegend's LEGEND MAX(TM) Human Mesothelin ELISA Kit is specifically designed for the accurate quantitation of Human Mesothelin from cell culture supernatant, serum, plasma or other bodily fluids. It is ready-to-use, accurate, and sensitive.