Significantly, these studies have shown durable responses in a multitude of patients with limited adverse events.21,22 Interestingly, larotrectinib was shown to induce partial response and restore iodine uptake in one case of RAI refractory adult thyroid cancer harboring the EML4-NTRK3 fusion,23 opening the way for similar therapies in pediatric tumors where these alterations are frequent and often associated with poor prognosis. The gene discussed is EML4; the disease is thyroid cancer.