This orally available, ATP-competitive inhibitor has shown excellent therapeutic potential against ROS1-driven fusion cancers, and significantly improved inhibitory activity compared with the first-generation-approved tyrosine kinase inhibitors (TKIs) including the ALK/mesenchymal–epithelial transition factor/ROS inhibitor, crizotinib (Xalkori)7, as well as next-generation ALK and ALK/ROS1 inhibitors, ceritinib and alectinib8, 9. Here, ALK is linked to cancer.