ALK and non-small cell lung carcinoma: Alectinib is a potent ALK tyrosine kinase inhibitor that effectively penetrates the central nervous system.[5,6] At the same time, activity has been demonstrated against several secondary ALK mutations that may arise following crizotinib treatment; however, the mutational spectrum of ALK may become increasingly complex in patients who have been treated with multiple ALK inhibitors.[7] Concomitant TP53 mutations may also affect the efficacy of alectinib, which has previously been associated with adverse outcomes in patients with advanced ALK-positive NSCLC receiving ALK inhibitors.[8-10]