HMGB1 and pleural mesothelioma: HMGB1 is released from mesothelial cells when they undergo necrosis induced by exposure to asbestos fibers [32, 36], and the released HMGB1 is involved in malignant transformation [34, 36–39], suggesting that rats developing fiber-associated pleural mesothelioma would be expected to have elevated levels of HMGB1 in their PLF.