{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"The S100A1 protein is a member of the S100 family of proteins containing 4 EF-hand calcium-binding motifs in its dimerized form. S100 protiens are localized in the cytoplasm and/or nucleus of a wide range of cells, and involved in the regulation of a number of cellular processes such as cell cycle progression and differentation. S100A1 may function in stimulation of Ca2+-induced Ca2+ release, inhibition of microtubule assembly and inhibition of protein kinase C-mediated phosphorylation."}]},{"type":"paragraph","children":[{"type":"text","value":"In normal tissues, anti-S100A1 is epxressed in cardiac muscle, skeletal muscle and neuronal cells. Reduced expression of S100A1 has been implicated in carciomyopathies. It can also be useful in distinguishing between Renal Onocytomas and Clear Cell Renal Cell Carcinomas (positive) and Papillary Renal Cell Carcinomas (positive) from Chromophobe Renal Cell Carcinomas (negative). It is a specific and sensitive marker for Nephrogenic Adenoma."}]}]}