Previous studies showed that NSCLC patients with ROS1 fusions are more predisposed to brain metastases22; 20–50% of NSCLC patients have brain metastases,22 and CNS is the site of initial progression in approximately half of ROS1 fusion-positive NSCLC patients treated with crizotinib,23 highlighting the importance of CNS activity for ROS1 TKIs. Here, ROS1 is linked to non-small cell lung carcinoma.