ROS1 and non-small cell lung carcinoma: In a trial of adult patients with advanced NSCLC that used blood liquid biopsies to assess circulating tumor DNA to determine whether patients with ROS1-positive NSCLC were treated with the entrectinib, the assay resulted in an 81% objective response rate to entrectinib, which is consistent with the results of a previous study using a tissue-based assay to identify ROS1 fusions (206).