HMGB1 and mesothelioma: Notably, They found that HMGB1 was present in the pleural lavage of rats treated with MWCNT-7, a rigid MWCNT, but not in rats treated with DWCNT, and the lack of HMGB1 in the pleural cavity was also observed in the DWCNT-treated rats that developed mesothelioma [9].