ROS1 and non-small cell lung carcinoma: Despite the available data on crizotinib for ROS1-rearranged NSCLC patients from clinical studies, real-world information on its use and outcomes beyond these strict trial settings remains limited [25,36,37,38], and hence the efficacy of crizotinib in ROS1-rearranged lung cancer patients with brain metastasis is also yet to be evaluated.