ROS1 and adenocarcinoma: In the study by Selinger et al., 0.4% (1/278) of resected stage I-III adenocarcinomas had a ROS1 fusion and Warth et al. (both used ROS1 IHC and FISH) found a prevalence of 1.2% (5/405) in resected adenocarcinomas [13, 14].