IL6 and Chylothorax: The endothelial cells lining lymphatic vessels have been shown to increase the permeability in response to proinflammatory cytokines such as IL-6, which are similar to those observed in the vascular endothelial cells.[19] As the chyle leakage occurred after the second peak of IL-6 production, our patient’s chylothorax is suggested to be attributed in part to IL-6 inducing lymphatic leakage.