Crizotinib, a small-molecule TKI targeting ALK, ROS1, and MET, has demonstrated significant antitumour activity in ROS1 fusion-positive NSCLC patients.[32,33] Entrectinib, another TKI approved for ROS1 fusion-positive NSCLC, has shown tumor reduction in most patients, including those with brain metastases.[34,35] However, these therapies are limited by poor BBB penetration and acquired drug resistance. The gene discussed is ALK; the disease is non-small cell lung carcinoma.