Malignant pleural effusion (MPE) is a significant problem most commonly caused by adenocarcinomas. Although tumors involving the pleura vary in their ability to produce MPE, pathways critical for MPE formation are poorly defined. We have found that mouse tumors harboring mutant (”)KRas produce MPE in mice while tumors without ”KRas do not. LLC and MC38 lung and colon adenocarcinomas, potent induce ...