{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Cytokeratins are intermediate-filament keratins found in the intracytoplasmic cytoskeleton of epithelial tissue. There are two types of cytokeratins: acidic type I cytokeratins and basic or neutral type II cytokeratins. Cytokeratins are usually found in pairs comprising a type I cytokeratin and a type II cytokeratin. Expression of these cytokeratins is frequently organ or tissue specific. Cytokeratin 5 (CK5) is a high-molecular weight, basic type II cytokeratin expressed in basal, intermediate and superficial-cell layers of stratified epithelia as well as transitional epithelia, complex epithelia, mesothelial cells and mesothelioma. CK 5 is expressed in most epithelial mesotheliomas but not by most pulmonary adenocarcinomas. ERG is a transcription factor, belonging to the ETS family. ERG is a regulator of embryonic development, influencing cell growth, differentiation, and angiogenesis. It is expressed at higher levels in early myelocytes than in mature lymphocytes. ERG can fuse with other genes. For example, fusion with TMPRSS2 to form an oncogenic fusion gene commonly found in prostate cancer. Fusion with the EWS gene is often observed in Ewing’s sarcoma."}]}]}