Mesothelial cells

Mesothelial cells form a monolayer (the mesothelium) that lines the body's serous cavities (pleural, pericardial, peritoneal) and covers the outer surface of internal organs. They produce a lubricating serous fluid that allows organs to move smoothly. They also provide a protective barrier, participate in immune surveillance and inflammation, and can undergo transition to a fibroblast-like phenotype (mesothelial-to-mesenchymal transition) in pathology.