ROS1 and serous adenocarcinoma: The RAS-MAPK signaling pathway (genomic alterations of NF1 at 16% and KRAS at 12% with mutual exclusivity), the PI3K-mTOR pathway (PIK3CA at 12% and TSC2 at 8%), and certain receptor tyrosine kinases (ROS1 at 9% and ERBB2 at 8%) might be candidates for targeted therapy in serous carcinomas.