Wenext turned to ceritinib, an effective first-line treatment for c-Rosoncogene 1 (ROS1)-rearranged nonsmall-cell lung cancer (NSCLC).16,17 Both crizotinib and ceritinib are recommended by the NCCN (NationalComprehensive Cancer Network) guidelines as first-line treatment forpatients with advanced ROS1+ NSCLC.17 Ceritinibinhibits ROS1 and has nanomolar-range half maximal inhibitory concentration(IC50) values in Ba/F3 cell lines engineered to expressthe oncogenic ROS1 rearrangement (IC50 = 180 nM) and inan NSCLC cell line HCC78 (IC50 = 50 nM).16 Here, ROS1 is linked to non-small cell lung carcinoma.