CLIC3 and Pleural effusion: Few studies have found that chloride intracellular channels 3 and 4, controlling the intracellular distribution of Cl- to provide ionic counterbalance, are over-expressed in human mesothelioma (22), and the concentration of Cl- in heart-failure-associated pleural effusion is higher than that in serum, indicating that Cl- may play an important role in the formation and retention of body fluid in the thoracic cavity (23).