NTRK1 and brain neoplasm: It has been shown to be active in a patient with a TRK-driven non-small cell lung cancer with cerebral metastases, suggesting the potential for this class of drugs to target primary intracranial tumours.13 In the recent report on larotrectinib efficacy in paediatric and adult clinical trials, 75% of patients with a TRK-driven tumour had an objective response to therapy.14 However, no patients were reported who had brain tumours harbouring TRK fusions, and the utility of this inhibitor for these HGG patients has, until now, been unknown.